Update updater.yml to run monthly rather than weekly

Author: smarie

.github/workflows/updater.yml

@@ -4,8 +4,8 @@ name: GitHub Actions Version Updater
 on:
   workflow_dispatch:
   schedule:
-    # Automatically run on every Sunday
-    - cron:  '0 0 * * 0'
+    # Automatically run on every first day of the month
+    - cron:  '0 0 1 * *'
 
 jobs:
   build: