update (virtual cluster) validation webhook registration to support admission.../v1

[mghlaiel]

What steps did you take and what happened: [A clear and concise description on how to REPRODUCE the bug.] I followed the README guide to deploy a virtual cluster on kind (kubernetes v1.24) then rancher RKE (kubernetes version 1.23)

kubectl vc create -f https://raw.githubusercontent.com/kubernetes-sigs/cluster-api-provider-nested/main/virtualcluster/config/sampleswithspec/virtualcluster_1_nodeport.yaml -o vc-1.kubeconfig
cannot find sts/etcd in ns default-95213e-vc-sample-1: statefulsets.apps "etcd" not found

Logs of the vc-manager pod:

k logs -n vc-manager  pods/vc-manager-6f855758c-cr4gv

{"level":"error","ts":1659554169.9459105,"logger":"entrypoint","msg":"unable to register webhooks to the manager","error":"fail to create validating webhook configuration: no matches for kind \"ValidatingWebhookConfiguration\" in version \"admissionregistration.k8s.io/v1beta1\""}

What did you expect to happen: A virtual cluster successfully created and kubeconfig output

Anything else you would like to add: [Miscellaneous information that will assist in solving the issue.]

Environment:

• cluster-api-provider-nested version: virtual cluster
• Minikube/KIND version: kind
• Kubernetes version: (use kubectl version): Major:"1", Minor:"24", GitVersion:"v1.24.3"
• OS (e.g. from /etc/os-release): Ubuntu 20.04.4

/kind bug [One or more /area label. See https://github.com/kubernetes-sigs/cluster-api-provider-nested/labels?q=area for the list of labels]