add stale stuff handling via workflow

.github/workflows/stale.yml

@@ -0,0 +1,32 @@
+# This workflow warns and then closes issues and PRs that have had no activity for a specified amount of time.
+#
+# You can adjust the behavior by modifying this file.
+# For more information, see:
+# https://github.com/actions/stale
+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+  - cron: '38 17 * * *'
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v8
+        with:
+          # issue setup
+          stale-issue-message: 'This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.'
+          close-issue-message: 'This issue was closed because it has been stalled for 5 days with no activity.'
+          exempt-issue-labels: 'accepted,enhancement,help wanted'
+          # pr setup
+          stale-pr-message: 'This PR is stale because it has been open 45 days with no activity. Remove stale label or comment'
+          exempt-pr-labels: 'help wanted,WIP'
+          days-before-pr-close: -1 # never close stale PRs
+          # deadlines config
+          days-before-stale: 30
+          days-before-close: 5