Build&push images for standalone releases too (#758)

Author: jotak

.github/workflows/release.yml

@@ -43,3 +43,6 @@ jobs:
           registry: quay.io
       - name: build and push manifest with images
         run: MULTIARCH_TARGETS="${{ env.WF_MULTIARCH_TARGETS }}" IMAGE_ORG=${{ env.WF_ORG }} VERSION=${{ env.tag }} CLEAN_BUILD=1 make images
+      - name: build and push manifest with images for standalone build
+        run: |
+          MULTIARCH_TARGETS="${{ env.WF_MULTIARCH_TARGETS }}" IMAGE_ORG=${{ env.WF_ORG }} VERSION=${{ env.tag }} CLEAN_BUILD=1 STANDALONE=true make images