Sync EnvTest version with k8s version

Author: gibizer

Makefile

@@ -54,7 +54,7 @@ OPERATOR_SDK_VERSION ?= v1.31.0
 DEFAULT_IMG ?= quay.io/openstack-k8s-operators/keystone-operator:latest
 IMG ?= $(DEFAULT_IMG)
 # ENVTEST_K8S_VERSION refers to the version of kubebuilder assets to be downloaded by envtest binary.
-ENVTEST_K8S_VERSION = 1.26
+ENVTEST_K8S_VERSION = 1.28
 
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))