proper apiversion for kubernetes > v1.22

[Doooooo0o]

fixes admissionregistration.k8s.io/v1beta1 MutatingWebhookConfiguration is deprecated in v1.16+, unavailable in v1.22+; use admissionregistration.k8s.io/v1 MutatingWebhookConfiguration error

[pgollangi]

@theonlydoo this has been moved to ingress-nginx space https://github.com/kubernetes/ingress-nginx/tree/main/images/kube-webhook-certgen , that repo has most recent fixes, including admissionregistration.k8s.io fixes. Your suggested changes included in the PR https://github.com/kubernetes/ingress-nginx/pull/7641

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