all: change module to google.golang.org/protobuf

Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.

Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/cmd/generate-protos/main.go b/internal/cmd/generate-protos/main.go
index 2d03750..1763a92 100644
--- a/internal/cmd/generate-protos/main.go
+++ b/internal/cmd/generate-protos/main.go
@@ -19,11 +19,11 @@
 	"sort"
 	"strings"
 
-	gengogrpc "github.com/golang/protobuf/v2/cmd/protoc-gen-go-grpc/internal_gengogrpc"
-	gengo "github.com/golang/protobuf/v2/cmd/protoc-gen-go/internal_gengo"
-	"github.com/golang/protobuf/v2/internal/detrand"
-	"github.com/golang/protobuf/v2/protogen"
-	"github.com/golang/protobuf/v2/reflect/protoreflect"
+	gengogrpc "google.golang.org/protobuf/cmd/protoc-gen-go-grpc/internal_gengogrpc"
+	gengo "google.golang.org/protobuf/cmd/protoc-gen-go/internal_gengo"
+	"google.golang.org/protobuf/internal/detrand"
+	"google.golang.org/protobuf/protogen"
+	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
 func init() {