perf(ci): remove redundant standalone CI run on push to main

CI was running 3 times per push (standalone + deploy + release).
Remove the direct push trigger since deploy.yml and release.yml
already call ci.yml via workflow_call. CI still runs standalone
on pull requests for fast feedback.

Author: Endika

.github/workflows/ci.yml

@@ -1,8 +1,6 @@
 name: CI
 
 on:
-  push:
-    branches: [main]
   pull_request:
     branches: [main]
   workflow_call: