ci: update renovate workflow schedule to run at 17 and 47 minutes past the hour

Run cronjob at 17 and 47 minutes past the hour, which are much quieter than the top/bottom of the hour.

Author: alan-agius4

.github/workflows/ng-renovate.yml

@@ -3,8 +3,8 @@ name: Angular-Org Renovate
 on:
   workflow_dispatch:
   schedule:
-    # Runs every 30 minutes.
-    - cron: '*/30 * * * *'
+    # Run on the 17th and 47th minute of every hour.
+    - cron: '17,47 * * * *'
 
 concurrency:
   group: ${{ github.workflow }}