chore(all): add a comment to the issue created by the Action (#2947)

Add a comment to the issue so that we can receive an email notification.

For #2874

Author: JoeWang1127

.github/workflows/librarian.yaml

@@ -77,7 +77,9 @@ jobs:
         run: |
           ISSUE_TITLE="all: tests failed at HEAD"
           BODY="Tests failed at HEAD of the \`main\` branch. Please review Workflow Run: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }} for detail."
-          gh issue create --title "$ISSUE_TITLE" --body "$BODY" --label ":rotating_light: critical" -R $GH_REPO
+          ISSUE_LINK=$(gh issue create --title "$ISSUE_TITLE" --body "$BODY" --label ":rotating_light: critical" -R $GH_REPO)
+          ISSUE_NUM=${ISSUE_LINK##*/}
+          gh issue comment $ISSUE_NUM --body "@googleapis/cloud-sdk-librarian-team A critical issue has been created, please respond immediately."
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GH_REPO: ${{ github.repository }}