move nightly cron job a little earlier

Author: RalfJung

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ on:
     branches:
       - 'master'
   schedule:
-    - cron: '6 6 * * *' # At 6:06 UTC every day.
+    - cron: '11 5 * * *' # At 5:11 UTC every day.
 
 env:
   CARGO_UNSTABLE_SPARSE_REGISTRY: 'true'