Add Stale workflow (#516)

* added stale workflow

.github/workflows/stale.yml

@@ -0,0 +1,25 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v4
+        with:
+          exempt-all-issue-assignees: true
+          stale-issue-message: 'This issue is stale because it has been open 120 days with no activity. Remove stale label or comment or this will be closed in 60 days.'
+          stale-issue-label: 'no-issue-activity'
+          exempt-issue-labels: 'awaiting-approval,work-in-progress,dontclose,documentation,security,pinned,future-enchancement,enchancement'
+          close-issue-message: 'This issue was closed because it has been stalled for 60 days with no activity.'
+          days-before-issue-close: 60
+          days-before-issue-stale: 120
+          exempt-all-pr-assignees: true
+          stale-pr-message: 'This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 30 days.'
+          close-pr-message: 'This PR was closed because it has been stalled for 30 days with no activity.'
+          days-before-pr-stale: 45
+          days-before-pr-close: 30
+          stale-pr-label: 'no-pr-activity'
+          exempt-pr-labels: 'awaiting-approval,work-in-progress,dontclose,documentation,security,pinned,future-enchancement,enchancement'