update main.yaml (#1551)

Author: sestinj

.github/workflows/main.yaml

@@ -11,8 +11,14 @@ on:
 
 if: github.event_name == 'push' || (github.event_name == 'pull_request' && github.event.pull_request.merged == true)
 
+  pull_request:
+    types: [closed]
+    branches:
+      - main
+
 jobs:
   build:
+    if: github.event_name == 'push' || (github.event_name == 'pull_request' && github.event.pull_request.merged == true)
     strategy:
       matrix:
         include: