chore(deps): update actions/stale action to v8 (#4438)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/stale.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: styfle/[email protected]
-      - uses: actions/stale@v4
+      - uses: actions/stale@v8
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           stale-issue-message: 'Thank you for your contribution! This issue is stale because it has been open 60 days with no activity. In order to keep it open, please remove stale label or add a comment within the next 10 days. If you need a Piper team member to remove the stale label make sure to add `@SAP/jenkins-library-team` to your comment.'