Don't run CI on push

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

.github/workflows/ci.yml

@@ -3,14 +3,8 @@ on:
   # When added to a merge queue.
   # See https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/configuring-pull-request-merges/managing-a-merge-queue#triggering-merge-group-checks-with-github-actions
   merge_group:
-  push:
-    branches:
-      - main
-      - "release/**"
   pull_request:
-    branches:
-      - main
-      - "release/**"
+    branches: ['main', 'release/**']
 
 env:
   # Go version we currently use to build containerd across all CI.