Bump actions/stale from 7.0.0 to 8.0.0 (#167)

Bumps [actions/stale](https://github.com/actions/stale) from 7.0.0 to 8.0.0.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](actions/stale@v7.0.0...v8.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Gilles Grousset <[email protected]>

Author: dependabot[bot]

.github/workflows/stale.yml

@@ -7,7 +7,7 @@ jobs:
   close-issues:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v7.0.0
+      - uses: actions/stale@v8.0.0
         with:
           days-before-issue-stale: 90
           days-before-issue-close: 14