Pull any new changes before pushing staleness updates.

This fixes some relatively harmless flakiness in our post-submit.  If two commits are made within ~5 minutes of each other, the `git push` command will fail because the git workspace isn't up to date.

PiperOrigin-RevId: 510165977

push_auto_update.sh

@@ -39,6 +39,7 @@ else
   commit_message="Auto-generate files"
 fi
 
+git pull --rebase
 git add -A
 git diff --staged --quiet || git commit -am "$commit_message"
 git push