GitHub Actions: Bump actions/stale from 4 to 8 and allow to trigger it manually (#7133)

* GitHub Actions: Bump actions/stale from 4 to 8

Bumps [actions/stale](https://github.com/actions/stale) from 4 to 8.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/stale/compare/v4...v8)

---
updated-dependencies:
- dependency-name: actions/stale
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Allow to trigger the stale workflow manually

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Armel Soro <asoro@redhat.com>

.github/workflows/stale.yaml

@@ -4,6 +4,7 @@ name: Mark and close stale issues and pull requests
 # to see all config knobs of the stale action.
 
 on:
+  workflow_dispatch:
   schedule:
   - cron: "0 0 * * *"
 
@@ -19,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/stale@v4
+    - uses: actions/stale@v8
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-issue-message: 'A friendly reminder that this issue had no activity for 90 days. Stale issues will be closed after an additional 30 days of inactivity.'