Use the existing docker-buildx Makefile target for cloudbuilds too instead of push-images python script

Makefile

@@ -1,8 +1,17 @@
 # Generated from kubebuilder template:
 # https://github.com/kubernetes-sigs/kubebuilder/blob/v4.11.1/pkg/plugins/golang/v4/scaffolds/internal/templates/makefile.go
 
+# IMAGE_TAG_BASE defines the namespace and part of the image name for remote images.
+IMAGE_TAG_BASE ?= mcp-lifecycle-operator
+
+# IMAGE_TAG defines the tag for the image.
+IMAGE_TAG ?= latest
+
+# GIT_IMAGE_TAG is a date-and-commit based tag for CI/release builds.
+GIT_IMAGE_TAG = v$(shell date +%Y%m%d)-$(shell git describe --always --dirty)
+
 # Image URL to use all building/pushing image targets
-IMG ?= controller:latest
+IMG ?= $(IMAGE_TAG_BASE):$(IMAGE_TAG)
 
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))
@@ -182,13 +191,10 @@ docker-push: ## Push docker image with the manager.
 PLATFORMS ?= linux/arm64,linux/amd64,linux/s390x,linux/ppc64le
 .PHONY: docker-buildx
 docker-buildx: ## Build and push docker image for the manager for cross-platform support
-	# copy existing Dockerfile and insert --platform=${BUILDPLATFORM} into Dockerfile.cross, and preserve the original Dockerfile
-	sed -e '1 s/\(^FROM\)/FROM --platform=\$$\{BUILDPLATFORM\}/; t' -e ' 1,// s//FROM --platform=\$$\{BUILDPLATFORM\}/' Dockerfile > Dockerfile.cross
 	- $(CONTAINER_TOOL) buildx create --name mcp-lifecycle-operator-builder
 	$(CONTAINER_TOOL) buildx use mcp-lifecycle-operator-builder
-	- $(CONTAINER_TOOL) buildx build --push --platform=$(PLATFORMS) --tag ${IMG} -f Dockerfile.cross .
+	- $(CONTAINER_TOOL) buildx build --push --platform=$(PLATFORMS) --tag ${IMG} $(foreach tag,$(EXTRA_TAGS),-t $(IMAGE_TAG_BASE):$(tag)) .
 	- $(CONTAINER_TOOL) buildx rm mcp-lifecycle-operator-builder
-	rm Dockerfile.cross
 
 .PHONY: build-installer
 build-installer: manifests generate kustomize ## Generate a consolidated YAML with CRDs and deployment.

cloudbuild.yaml

@@ -1,16 +1,12 @@
 timeout: 2700s
 steps:
-  # This step runs the python script to build and push the Docker image.
-  # We use the gcloud builder because it comes with python and the docker client.
   - name: "gcr.io/k8s-staging-test-infra/gcb-docker-gcloud"
-    entrypoint: "python3"
+    entrypoint: "make"
     args:
-      - "./dev/tools/push-images"
-      # Assuming the script accepts project and tag arguments.
-      # Using standard Cloud Build substitutions.
-      - "--image-prefix=${_IMAGE_PREFIX}/"
-      - "--extra-image-tag=${_GIT_TAG}-${_CONFIG}"
-      - "--extra-image-tag=latest-${_CONFIG}"
+      - "docker-buildx"
+      - "IMAGE_TAG_BASE=${_IMAGE_PREFIX}/mcp-lifecycle-operator"
+      - "IMAGE_TAG=$$(GIT_IMAGE_TAG)"
+      - "EXTRA_TAGS=${_GIT_TAG}-${_CONFIG} latest-${_CONFIG}"
 
 options:
   enableStructuredLogging: true