arm: do not rely on host arch, specify --platform and CGO_ENABLED

Since we are building arm on arm64 machines we have to specify the desired platform
and not rely on the host's architecture.

Also when building arm on arm64 machines, there can be issues with cgo.
So this patch makes sure CGO_ENABLED env var gets passed on as a build arg.

Signed-off-by: Tibor Vass <tibor@docker.com>

Makefile

@@ -75,5 +75,5 @@ deb: checkout ## build deb packages
 static: DOCKER_BUILD_PKGS:=static-linux cross-mac cross-win cross-arm
 static: checkout ## build static-compiled packages
 	for p in $(DOCKER_BUILD_PKGS); do \
-		$(MAKE) -C $@ VERSION=$(VERSION) GO_VERSION=$(GO_VERSION) $${p}; \
+		$(MAKE) -C $@ VERSION=$(VERSION) GO_VERSION=$(GO_VERSION) TARGETPLATFORM=$(TARGETPLATFORM) $${p}; \
 	done

static/Makefile

@@ -74,7 +74,7 @@ cross-arm: cross-all-cli ## create tgz with linux armhf client only
 
 .PHONY: static-cli
 static-cli:
-	$(MAKE) -C $(CLI_DIR) -f docker.Makefile VERSION=$(GEN_STATIC_VER) build
+	cd $(CLI_DIR) && VERSION=$(GEN_STATIC_VER) docker buildx bake --set binary.platform=$(TARGETPLATFORM) --set binary.args.CGO_ENABLED=$(CGO_ENABLED) binary
 
 .PHONY: static-engine
 static-engine: