Update actions/stale action to v5 (#149)

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Luke Tainton <ltainton@cisco.com>

.github/workflows/stale.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/stale@v4
+    - uses: actions/stale@v5
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-issue-message: 'This issue has been marked as stale due to inactivity. If this issue is still ongoing, please leave a comment.'