[cluster-agent] apiextensions.k8s.io version should be update for CustomResourceDefinition

[dje4om]

Hi,

Message from a 1.20 cluster :

Warning: apiextensions.k8s.io/v1beta1 CustomResourceDefinition is deprecated in v1.16+, unavailable in v1.22+; use apiextensions.k8s.io/v1 CustomResourceDefinition

According to kubernetes releases, it seems like a good time to update this reference.

[laxmansoma22]

did you face any issues after updating to v1 version...