Fix go pattern in .pre-commit-config.yaml

Author: redsun82

.pre-commit-config.yaml

@@ -31,7 +31,7 @@ repos:
 
       - id: go-gen
         name: Check checked in generated files in go
-        files: go/.*
+        files: ^go/.*
         language: system
         entry: bazel run //go:gen
         pass_filenames: false