Update docker-build-and-push.yml

Author: Roopan-Microsoft

.github/workflows/docker-build-and-push.yml

@@ -22,6 +22,7 @@ on:
 
 jobs:
   build-and-push:
+    if: github.event.pull_request.merged == true || github.event_name == 'workflow_dispatch'
     runs-on: ubuntu-latest
 
     steps: