Drop usage of `kube-rbac-proxy`

# Summary

Starting early 2025 the support for `kube-rbac-proxy` will be discontinued in favor of the usage of `authn/authz`. We need to remove the usage of `kube-rbac-proxy` from this project and replace it accordingly following the community provided guide: https://github.com/kubernetes-sigs/kubebuilder/blob/master/docs/book/src/reference/metrics.md#important-if-you-are-using-kube-rbac-proxy