[gha] Use per-commit webdev sync branches (#519)

Use per-commit webdev sync branches

Author: coreymartin

.github/workflows/test-release-sync.yaml

@@ -368,7 +368,7 @@ jobs:
 
           curl https://lsdev-repo.s3-us-west-2.amazonaws.com/github-actions/copybara_deploy.jar --output ./copybara.jar
           trap on_exit EXIT
-          java -jar copybara.jar ./copy.bara.sky js-sdk-push-to-webdev --nogit-destination-rebase
+          java -jar copybara.jar ./copy.bara.sky js-sdk-push-to-webdev "${GITHUB_SHA}" --nogit-destination-rebase --github-destination-pr-branch="js-sdk-sync-${GITHUB_SHA}"
 
       - name: "Notify failure on Slack"
         if: "failure() && github.event_name == 'push'"