Add handling for stale issues and PRs

As discussed in the community meeting stale issues and PRs
will be warned and stale labeled after 60 days. Without any
further action the auto close happens after 30 days of the
stale notification

Author: schaefi

.github/workflows/ci-stale.yml

@@ -0,0 +1,14 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v10
+        with:
+          stale-issue-message: 'This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days.'
+          days-before-stale: 60
+          days-before-close: 30