Separate Push CI images from Scheduled CI (#19170)

* separate images

* Fix condition

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

.github/workflows/self-push-caller.yml

@@ -40,6 +40,8 @@ jobs:
     needs: check-for-setup
     if: (github.event_name == 'push') && (needs.check-for-setup.outputs.changed == '1')
     uses: ./.github/workflows/build-docker-images.yml
+    with:
+      image_postfix: "-push-ci"
     secrets: inherit
 
   run_push_ci: