chore: tweak kokoro config (via synth) (#129)

* chore(python): skip docfx in main presubmit

* chore(python): skip docfx in main presubmit

* fix: properly template the repo name

Source-Author: Bu Sun Kim <8822365+busunkim96@users.noreply.github.com>
Source-Date: Fri Jan 8 10:32:13 2021 -0700
Source-Repo: googleapis/synthtool
Source-Sha: fb53b6fb373b7c3edf4e55f3e8036bc6d73fa483
Source-Link: https://github.com/googleapis/synthtool/commit/fb53b6fb373b7c3edf4e55f3e8036bc6d73fa483

* chore: add missing quotation mark

Source-Author: Bu Sun Kim <8822365+busunkim96@users.noreply.github.com>
Source-Date: Mon Jan 11 09:43:06 2021 -0700
Source-Repo: googleapis/synthtool
Source-Sha: 16ec872dd898d7de6e1822badfac32484b5d9031
Source-Link: https://github.com/googleapis/synthtool/commit/16ec872dd898d7de6e1822badfac32484b5d9031
diff --git a/synth.metadata b/synth.metadata
index 1e35d07..d10948c 100644
--- a/synth.metadata
+++ b/synth.metadata
@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/python-api-core.git",
-        "sha": "b51b7f587042fe9340371c1b5c8e9adf8001c43a"
+        "sha": "abc3d88466a1e55cf459e6c78a6fb7343a29df6f"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "41a4e56982620d3edcf110d76f4fcdfdec471ac8"
+        "sha": "16ec872dd898d7de6e1822badfac32484b5d9031"
       }
     }
   ],