chore(deps): update actions/stale digest to 5bef64f (#2815)

Co-authored-by: Andrew Peabody <andrewpeabody@google.com>

Author: renovate-bot

.github/workflows/stale.yml

@@ -26,7 +26,7 @@ jobs:
     if: github.repository_owner == 'GoogleCloudPlatform'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/stale@28ca1036281a5e5922ead5184a1bbf96e5fc984e # v9
+    - uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9.1.0
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-issue-message: 'This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days'