Bump actions/stale from 5 to 7 (#85)

Bumps [actions/stale](https://github.com/actions/stale) from 5 to 7.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](actions/stale@v5...v7)

---
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>

Author: dependabot[bot]

.github/workflows/stale.yml

@@ -11,7 +11,7 @@ jobs:
             pull-requests: write
 
         steps:
-            -   uses: actions/stale@v5
+            -   uses: actions/stale@v7
                 with:
                     repo-token: ${{ secrets.GITHUB_TOKEN }}
                     stale-issue-message: "This issue is stale because it has been open 21 days with no activity. Remove stale label or comment or this will be closed in 7 days."