fix(insider): spreadhead workflow must not be executed by a push or a PR

.github/workflows/insider-spearhead.yml

@@ -4,14 +4,6 @@ on:
   workflow_dispatch:
   schedule:
     - cron: '0 0 * * *'
-  push:
-    branches: [ insider ]
-    paths-ignore:
-    - '**/*.md'
-  pull_request:
-    branches: [ insider ]
-    paths-ignore:
-    - '**/*.md'
 
 jobs:
   build: