fix(CD): try to fix workflow triggering

Author: benjGam

.github/workflows/cd.yml

@@ -1,10 +1,13 @@
 name: Node.js CD
 
 on:
-  push:
-    branches: ['main']
+  pull_request:
+    branches:
+      - main
+    types: [closed]
 
 jobs:
+  if: ${{ github.event.pull_request.merged }}
   publish-npm:
     runs-on: ubuntu-latest
     steps: