chore: Migrate old probot stale config to github actions (argoproj#877)

Signed-off-by: Marco Kilchhofer <[email protected]>

.github/workflows/stale.yml

@@ -1,3 +1,4 @@
+## Reference: https://github.com/actions/stale
 name: Mark stale issues and pull requests
 on:
   schedule:
@@ -9,7 +10,22 @@ jobs:
     - uses: actions/stale@v3
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: 'Stale issue message'
-        stale-pr-message: 'Stale pull request message'
+        # Number of days of inactivity before an issue becomes stale
+        days-before-stale: 60
+        # Number of days of inactivity before a stale issue is closed
+        days-before-close: 7
+        # Issues with these labels will never be considered stale
+        exempt-issue-labels: "on-hold,pinned,security"
+        exempt-pr-labels: "on-hold,pinned,security"
+        # Comment to post when marking an issue as stale.
+        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.
+        stale-pr-message: >
+          This pull request 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.
+        # Label to use when marking an issue as stale
         stale-issue-label: 'no-issue-activity'
         stale-pr-label: 'no-pr-activity'