New stale action

This PR adds a new github stale action. This will replace our previous (and now deprecated) stalebot. Two notable differences are that issues will now go stale after 45 days of inactivity, and the most commonly used priority labels have been added for exemption.

Docs and list of inputs for stale action for reference here.

Signed-off-by: caroline-suse-rancher <caroline.davis@suse.com>

.github/workflows/stale.yml

@@ -0,0 +1,51 @@
+name: Stalebot
+on:
+  schedule:
+    - cron: '0 20 * * *'
+  workflow_dispatch:
+permissions:
+  contents: write
+  issues: write
+jobs:
+  stalebot:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Close Stale Issues
+        uses: actions/stale@v9.0.0
+        with:
+          # ensure PRs are exempt
+          days-before-pr-stale: -1
+          day-before-pr-closed: -1
+          
+          days-before-issue-stale: 45
+          days-before-issue-close: 14
+          stale-issue-label: status/stale
+          exempt-all-milestones: true
+          exempt-all-assignees: true
+          exempt-issue-labels:
+            internal,
+            kind/bug,
+            kind/bug-qa,
+            kind/task,
+            kind/feature,
+            kind/enhancement,
+            kind/design,
+            kind/ci-improvements,
+            kind/performance,
+            kind/flaky-test,
+            kind/documentation,
+            kind/epic,
+            kind/upstream-issue,
+            priority/backlog,
+            priority/critical-urgent,
+            priority/important-longterm,
+            priority/important-soon,
+            priority/low,
+            priority/medium,
+            priority/high,
+            priority/urgent,
+          stale-issue-message: > 
+            This repository uses a bot to automatically label issues which have not had any activity (commit/comment/label) 
+            for 45 days. This helps us manage the community issues better. If the issue is still relevant, please add a comment to the 
+            issue so the bot can remove the label and we know it is still valid. If it is no longer relevant (or possibly fixed in the 
+            latest release), the bot will automatically close the issue in 14 days. Thank you for your contributions.