build: try a different conditional event for pushing images (#182)

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
     - name: push image
       id: push-to-registry
       # Push *only* after the merge. Until I actually need to push PR images, why waste storage?
-      if: github.event.pull_request.merged == true
+      if: github.event_name == 'push'
       uses: redhat-actions/push-to-registry@v2
       with:
         image: ${{ steps.build-image.outputs.image }}
@@ -36,5 +36,5 @@ jobs:
         password: ${{ secrets.REGISTRY_PASSWORD }}
 
     - name: Show image url
-      if: github.event.pull_request.merged == true
+      if: github.event_name == 'push'
       run: echo "Image pushed to ${{ steps.push-to-registry.outputs.registry-paths }}"