Revert to regular CI cron job

Author: vietj

.github/workflows/ci-5.x-stable.yml

@@ -7,7 +7,7 @@ on:
     branches:
       - '5.[0-9]+'
   schedule:
-    - cron: '*/10 * * * *'
+    - cron: '0 6 * * *'
 jobs:
   CI-CD:
     uses: ./.github/workflows/ci-matrix-5.x.yml