⬆️ Bump actions/stale from 3 to 6

Bumps [actions/stale](https://github.com/actions/stale) from 3 to 6.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](actions/stale@v3...v6)

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

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

Author: dependabot[bot]

.github/workflows/stale.yml

@@ -6,7 +6,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/stale@v3
+    - uses: actions/stale@v6
       with:
         repo-token: ${{ secrets.GH_PAT }}
         stale-issue-message: "⚠️ This issue has not seen any activity in the past 2 months so I'm marking it as stale. I'll close it if it doesn't see any activity in the coming week."