[PRMT-4356] Refactored submit-dependency-graph.yml workflow to only r…

…un when a PR is merged into main

.github/workflows/submit-dependency-graph.yml

@@ -1,6 +1,8 @@
 name: Submit dependency graph
 on:
-  push:
+  pull_request:
+    types: [closed]
+    branches: [main]
 
 permissions:
   contents: write