make generate-operator-yaml is broken: wrong kustomize module path and kustomize v2.0.3 no longer compiles

make generate-operator-yaml has not worked for a long time, for two independent reasons:

1. Wrong module path in the Makefile. The target runs go run github.com/kubernetes-sigs/kustomize build ./deploy, but the module in go.mod is sigs.k8s.io/kustomize, so go run fails immediately:

   no required module provides package github.com/kubernetes-sigs/kustomize; to add it:
   	go get github.com/kubernetes-sigs/kustomize
   

   That line has been unchanged since 44f9afd (October 2020).

2. The pinned kustomize no longer compiles. With the path corrected, sigs.k8s.io/kustomize v2.0.3+incompatible (from 2019) fails to build against the current k8s.io/kube-openapi on main:

   # sigs.k8s.io/kustomize/pkg/transformers/config
   sigs.k8s.io/kustomize@v2.0.3+incompatible/pkg/transformers/config/factorycrd.go:71:25: cannot use api.Schema.SchemaProps.Properties (variable of type map[string]"k8s.io/kube-openapi/pkg/validation/spec".Schema) as myProperties value in argument to looksLikeAk8sType
   

As a result the only way to rebuild build/_output/operator.yaml (and the bundle in test/endtoend/operator/operator-latest.yaml that the end-to-end tests and quickstart docs use) is with an out-of-tree kustomize.

Proposed fix

• Replace the sigs.k8s.io/kustomize v2 tool dependency in tools/tools.go and go.mod with the current CLI module, sigs.k8s.io/kustomize/kustomize/v5, following the existing go run tool convention used for controller-gen and gen-crd-api-reference-docs.
• Point the Makefile target at that module and create build/_output if needed.
• Verify the output matches test/endtoend/operator/operator-latest.yaml apart from the PR image override.