Add stale workflow

Signed-off-by: Joana Hrotko <joana.hrotko@docker.com>

.github/workflows/stale.yml

@@ -0,0 +1,31 @@
+name: 'Close stale issues'
+on:
+  # schedule:
+  #   - cron: '0 0 * * *' # at midnight UTC every day
+  pull_request:
+  workflow_dispatch:
+    inputs:
+      debug_enabled:
+        description: 'To run in debug mode'
+        required: false
+        default: "true"
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - uses: actions/stale@v9
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          debug-only: ${{ github.event.inputs.debug_enabled }}
+          stale-issue-message: >
+            This issue has been automatically marked as stale because it has not had
+            recent activity. It will be closed if no further activity occurs. Thank you
+            for your contributions.
+          days-before-issue-stale: 180
+          days-before-issue-close: 180
+          stale-issue-label: "stale"
+          exempt-issue-labels: "kind/feature,kind/enhancement"
+