Bump actions/stale from 8 to 9 (#859)

Bumps [actions/stale](https://github.com/actions/stale) from 8 to 9.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](actions/stale@v8...v9)

---
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>

.github/workflows/stale.yml

@@ -39,7 +39,7 @@ jobs:
         with:
           path: https://raw.githubusercontent.com/conda/infra/main/.github/messages.yml
 
-      - uses: actions/stale@v8
+      - uses: actions/stale@v9
         id: stale
         with:
           # Only issues with these labels are checked whether they are stale