build(deps): bump actions/stale from 6 to 8

Bumps [actions/stale](https://github.com/actions/stale) from 6 to 8.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](actions/stale@v6...v8)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/stale.yml

@@ -13,7 +13,7 @@ jobs:
       pull-requests: write  # for actions/stale to close stale PRs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v6
+      - uses: actions/stale@v8
         with:
           repo-token: ${{ github.token }}
           days-before-stale: 21