chore: Update discovery artifacts (#1430)

## Deleted keys were detected in the following pre-stable discovery artifacts:
run v1alpha1 https://github.com/googleapis/google-api-python-client/commit/db18e29c7f616f212121960fe8efd6fb7cdf9b22

## Discovery Artifact Change Summary:
feat(artifactregistry): update the api https://github.com/googleapis/google-api-python-client/commit/bc9a38bf901a63525fb4c7b1e94fd4ce5fb441c3
feat(chat): update the api https://github.com/googleapis/google-api-python-client/commit/eea3c5c177aaded427fd3b5bab80812bf748ef79
feat(cloudasset): update the api https://github.com/googleapis/google-api-python-client/commit/2e31dd0b58d3c656df5aaa042994c637d0100f97
feat(cloudbuild): update the api https://github.com/googleapis/google-api-python-client/commit/3a3b420d53aabe1fdf6ddca483a3d164f72d6268
feat(composer): update the api https://github.com/googleapis/google-api-python-client/commit/78c0d8decbe640c522c45850c97002e7da12f4e0
feat(container): update the api https://github.com/googleapis/google-api-python-client/commit/a54737fe763fd288e54505faace58040cbf8920b
feat(datafusion): update the api https://github.com/googleapis/google-api-python-client/commit/f6bf3c6b92fbf7072798b987998bf55ee9276389
feat(dataproc): update the api https://github.com/googleapis/google-api-python-client/commit/3fde9a3604e4811ce02f1062dcee9cef35b1ad51
feat(documentai): update the api https://github.com/googleapis/google-api-python-client/commit/79c556d389889fb0f48c8cc5ad5ab4a2caaab603
feat(groupssettings): update the api https://github.com/googleapis/google-api-python-client/commit/d537f96a20a699629fa85fbdeadb74ead3b32699
feat(logging): update the api https://github.com/googleapis/google-api-python-client/commit/d3548c505e4b1065365584493d15f21a19639626
feat(monitoring): update the api https://github.com/googleapis/google-api-python-client/commit/d24af68a9621fda9d7a576d3615178604a1482d2
feat(paymentsresellersubscription): update the api https://github.com/googleapis/google-api-python-client/commit/cff9039529278d95cee936826b5406867c638430
feat(redis): update the api https://github.com/googleapis/google-api-python-client/commit/46102d1726393f872420820e6200bb83cefd74b6
feat(run): update the api https://github.com/googleapis/google-api-python-client/commit/db18e29c7f616f212121960fe8efd6fb7cdf9b22
feat(slides): update the api https://github.com/googleapis/google-api-python-client/commit/68634cd565914e6003c851ec5f43fa2ff290afca
feat(spanner): update the api https://github.com/googleapis/google-api-python-client/commit/289512124fc77a69957b912f06e9c3d315aa0526
feat(storagetransfer): update the api https://github.com/googleapis/google-api-python-client/commit/24895f156f10c03f2da686be95d8c70ea34008a3
diff --git a/docs/dyn/dialogflow_v2.projects.agent.environments.html b/docs/dyn/dialogflow_v2.projects.agent.environments.html
index d6512d6..47de8ae 100644
--- a/docs/dyn/dialogflow_v2.projects.agent.environments.html
+++ b/docs/dyn/dialogflow_v2.projects.agent.environments.html
@@ -127,7 +127,7 @@
     The object takes the form of:
 
 { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-  "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+  "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
   "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
   "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
     "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.
@@ -182,7 +182,7 @@
   An object of the form:
 
     { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-  "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+  "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
   "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
   "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
     "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.
@@ -261,7 +261,7 @@
   An object of the form:
 
     { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-  "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+  "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
   "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
   "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
     "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.
@@ -369,7 +369,7 @@
     { # The response message for Environments.ListEnvironments.
   "environments": [ # The list of agent environments. There will be a maximum number of items returned based on the page_size field in the request.
     { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-      "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+      "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
       "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
       "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
         "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.
@@ -442,7 +442,7 @@
     The object takes the form of:
 
 { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-  "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+  "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
   "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
   "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
     "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.
@@ -498,7 +498,7 @@
   An object of the form:
 
     { # You can create multiple versions of your agent and publish them to separate environments. When you edit an agent, you are editing the draft agent. At any point, you can save the draft agent as an agent version, which is an immutable snapshot of your agent. When you save the draft agent, it is published to the default environment. When you create agent versions, you can publish them to custom environments. You can create a variety of custom environments for: - testing - development - production - etc. For more information, see the [versions and environments guide](https://cloud.google.com/dialogflow/docs/agents-versions).
-  "agentVersion": "A String", # Required. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
+  "agentVersion": "A String", # Optional. The agent version loaded into this environment. Supported formats: - `projects//agent/versions/` - `projects//locations//agent/versions/`
   "description": "A String", # Optional. The developer-provided description for this environment. The maximum length is 500 characters. If exceeded, the request is rejected.
   "fulfillment": { # By default, your agent responds to a matched intent with a static response. As an alternative, you can provide a more dynamic response by using fulfillment. When you enable fulfillment for an intent, Dialogflow responds to that intent by calling a service that you define. For example, if an end-user wants to schedule a haircut on Friday, your service can check your database and respond to the end-user with availability information for Friday. For more information, see the [fulfillment guide](https://cloud.google.com/dialogflow/docs/fulfillment-overview). # Optional. The fulfillment settings to use for this environment.
     "displayName": "A String", # Optional. The human-readable name of the fulfillment, unique within the agent. This field is not used for Fulfillment in an Environment.