Fix CI duplicated checks by configuring workflow triggers properly

Co-authored-by: nomeguy <85475922+nomeguy@users.noreply.github.com>

Author: Copilot

.github/workflows/main.yml

@@ -1,5 +1,9 @@
 name: main
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - main
+  pull_request:
 jobs:
   test:
     runs-on: ubuntu-latest