add stale action

Author: bmarwell

.github/workflows/stale.yml

@@ -0,0 +1,15 @@
+name: 'Close stale PR'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v4
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          stale-pr-message: 'This PR is stale because it has been open 365 days with no activity. Remove stale label or comment or this will be closed in 30 days.'
+          days-before-stale: 365
+          days-before-pr-close: 30