Remove push: on nightly

.github/workflows/nightly.yml

@@ -3,7 +3,6 @@ name:  Nightly
 on:
   schedule:
     - cron: 0 20 * * *
-  push:
 
 jobs:
   build_windows:
@@ -136,4 +135,4 @@ jobs:
           python3 ci/create_nightly_json.py "$BUCKET" > nightly.json
           b2 upload-file "$BUCKET" nightly.json nightly.json
 
-          b2 clear-account
+          b2 clear-account