Explicitly ban changes to workflow files from forked PRs
Changes to these files *can't* be tested in forked PRs, so we should explicitly block them with an error message to explain why.
PiperOrigin-RevId: 508701535
diff --git a/.github/workflows/test_runner.yml b/.github/workflows/test_runner.yml
index f897c65..3d67401 100644
--- a/.github/workflows/test_runner.yml
+++ b/.github/workflows/test_runner.yml
@@ -40,8 +40,8 @@
branches:
- main
- '[0-9]+.x'
- # The 21.x and 22.x branches still use Kokoro
- - '!2[12].x'
+ # The 21.x branch still use Kokoro
+ - '!21.x'
# For testing purposes so we can stage this on the `gha` branch.
- gha
types: [labeled, opened, reopened, synchronize]
