fix action schedule (#235)

Author: baermat

.github/workflows/makefile.yml

@@ -6,8 +6,7 @@ on:
   pull_request:
     branches: [ "master" ]
   schedule:
-    - cron: '0 13 * * *' # 13:00 server time, meaning 14/15:00 our time. For regular commits in LS. GitHub seems to be quite busy at that time, so this might be executed much later
-    - cron: '0 7 * * *'  # 07:00 server time, meaning 08/09:00 our time. For the night owls and early birds.
+    - cron: '0 13 * * 1' 
 jobs:
   test:
     runs-on: ubuntu-latest