Enable labeling issues as idle (mdn#10747)

* Add workflow to mark idle issues and PRs

* Increase frequency for dry-run

* Enable idle issue labeling

* Delay first run

.github/workflows/idle-issues.yml

@@ -1,7 +1,7 @@
 name: 'Mark issues and pull requests as idle'
 on:
   schedule:
-    - cron: '55 * * * *'
+    - cron: '49 11,23 * * *'
 
 jobs:
   idle:
@@ -16,6 +16,5 @@ jobs:
           stale-issue-label: 'idle'
           stale-pr-label: 'idle'
           enable-statistics: true
-          # debugging/dry-run stuff
-          debug-only: true
-          operations-per-run: 1000
+          ascending: true  # oldest first, for now
+          operations-per-run: 100