Migrate to actions/stale v4.0

.github/workflows/stale-bot

@@ -8,7 +8,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v3
+      - uses: actions/stale@v4
         with:
           stale-issue-message: 'We are clearing up our old issues and your ticket has been open for 6 months with no activity. Remove stale label or comment or this will be closed in 7 days.'
           stale-pr-message: ''We are clearing up our old Pull Requests and yours has been open for 6 months with no activity. Remove stale label or comment or this will be closed in 7 days.'