Makefile: drop custom s390x envtest setup

setup-envtest seems to support s390x also:
$ setup-envtest list --os linux --arch s390x
(available)  v1.31.0  linux/s390x
(available)  v1.30.3  linux/s390x
(available)  v1.30.2  linux/s390x
(available)  v1.30.0  linux/s390x
(available)  v1.29.5  linux/s390x
(available)  v1.29.4  linux/s390x
(available)  v1.29.3  linux/s390x
(available)  v1.29.1  linux/s390x
(available)  v1.29.0  linux/s390x
(available)  v1.28.3  linux/s390x
(available)  v1.28.0  linux/s390x
(available)  v1.27.1  linux/s390x
(available)  v1.26.1  linux/s390x
(available)  v1.26.0  linux/s390x
(available)  v1.25.0  linux/s390x
(available)  v1.24.2  linux/s390x
(available)  v1.24.1  linux/s390x
(available)  v1.23.5  linux/s390x

Signed-off-by: Mikko Ylinen <[email protected]>

Makefile

@@ -59,24 +59,6 @@ else
 GOBIN=$(shell go env GOBIN)
 endif
 
-ifeq ($(ARCH),s390x)
-K8S_VERSION=v1.24.2
-ETCD_VERSION=v3.5.4
-ETCD_BASE_NAME=etcd-$(ETCD_VERSION)-linux-$(ARCH)
-KUBEBUILDER_PATH=$${PWD}/kubebuilder-tools/bin
-# ATM, there is no s390x support for kubebuilder-tools.
-# We need to prepare core binaries without envtest.
-# $1: a path where binaries are installed
-define INSTALL_KUBEBUILDER_TOOLS
-$(shell mkdir -p $1 && cd $1 && \
-curl -sLO https://dl.k8s.io/$(K8S_VERSION)/bin/linux/$(ARCH)/kube-apiserver && \
-curl -sLO https://dl.k8s.io/$(K8S_VERSION)/bin/linux/$(ARCH)/kubectl && \
-chmod +x kube-apiserver kubectl && \
-curl -sLO https://github.com/coreos/etcd/releases/download/$(ETCD_VERSION)/$(ETCD_BASE_NAME).tar.gz && \
-tar xzf $(ETCD_BASE_NAME).tar.gz && cp $(ETCD_BASE_NAME)/etcd . && rm -rf $(ETCD_BASE_NAME)*)
-endef
-endif
-
 # Setting SHELL to bash allows bash commands to be executed by recipes.
 # Options are set to exit when a recipe line exits non-zero or a piped command fails.
 SHELL = /usr/bin/env bash -o pipefail
@@ -122,12 +104,7 @@ vet: ## Run go vet against code.
 
 .PHONY: test
 test: manifests generate fmt vet envtest ## Run tests.
-ifeq ($(ARCH),s390x)
-	$(call INSTALL_KUBEBUILDER_TOOLS,$(KUBEBUILDER_PATH))
-	KUBEBUILDER_ASSETS="$(KUBEBUILDER_PATH)" go test ./... -coverprofile cover.out
-else
 	KUBEBUILDER_ASSETS="$(shell $(ENVTEST) use $(ENVTEST_K8S_VERSION) -p path)" go test ./... -coverprofile cover.out
-endif
 
 ##@ Build