Add Github action to close stale issues

The added workflow will close up to 30 old issues every day.
Issues that have been inactive for more than a year will be
first marked as stale, and if they remain stale after 15 days
they will be automatically closed.

Author: AmirhosseinPoolad

.github/workflows/stale.yml

@@ -0,0 +1,31 @@
+name: 'Close Stale Issues'
+on:
+  schedule:
+    # Run everyday at 1 PM UTC
+    - cron: '0 13 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          # The message to be shown for stale issues
+          stale-issue-message: 'This issue has been inactive for a year and has been marked as stale. It will be closed in 15 days if it continues to be stale. If you believe this is still an issue, please add a comment.'
+          close-issue-message: 'This issue has been marked stale for 15 days and has been automatically closed.'
+          # If you want to exempt an issue from being marked stale/deleted, label it as 'no-stale'
+          exempt-issue-labels: 'no-stale'
+          days-before-issue-stale: 365
+          days-before-issue-close: 15
+          # Start from the oldest issues
+          ascending: true
+          
+          # The configuration below can be used to allow the same behaviour with PRs.
+          # Since we currently don't want to close old PRs, it is commented out but 
+          # left here in case we change our mind.
+
+          # stale-pr-message: 'This PR has been inactive for a year and has been marked as stale. It will be closed in 15 days if it continues to be stale. If you are still working on this PR, please add a comment.'
+          # close-pr-message: 'This PR has been marked stale for 15 days and has been automatically closed.'
+          # exempt-pr-labels: 'no-stale'
+          # days-before-pr-stale: 365
+          # days-before-pr-close: 15