chore(deps): update dependency kubernetes/kubernetes to v1.31.4

Makefile

@@ -52,7 +52,7 @@ OPERATOR_SDK_VERSION ?= v1.38.0 # github-releases:operator-framework/operator-sd
 # Image URL to use all building/pushing image targets
 IMG ?= drpsychick/mailu-operator:$(VERSION)
 # ENVTEST_K8S_VERSION refers to the version of kubebuilder assets to be downloaded by envtest binary.
-ENVTEST_K8S_VERSION = 1.31.0 # github-releases:kubernetes/kubernetes
+ENVTEST_K8S_VERSION = 1.31.4 # github-releases:kubernetes/kubernetes
 
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))