Remove legacy docker build target

Makefile

@@ -30,18 +30,14 @@ help: ## Show this help
 	@grep -E -h '\s##\s' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'
 
 .PHONY: build
-build: build-bin build-docker ## All-in-one build
+build: build-bin docker-build ## All-in-one build
 
 .PHONY: build-bin
 build-bin: export CGO_ENABLED = 0
 build-bin: fmt vet ## Build binary
 	env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
 	go build -o $(BIN_FILENAME) .
 
-.PHONY: build-docker
-build-docker: build-bin ## Build docker image
-	$(DOCKER_CMD) build --platform linux/amd64 -t $(CONTAINER_IMG) .
-
 .PHONY: test
 test: test-go ## All-in-one test