Update K8s libraries to v1.33.1

[antoninbas]

• Update K8s libraries to v1.33.1
• Update sigs.k8s.io/controller-runtime to v0.21.0
• Update go.uber.org/mock to v0.5.2
• Update controller-gen to v0.18.0

Some of the key changes that were cause by these updates:

• Setting the EffectiveVersion in the generic apiserver config is now done differently. As a reminder, we only need this field so that the /version endpoint returns a meaningful value.
• The code generated for by client-gen for fake clients (client-go) is now more generic (it leverages Go generics), so as a result the generated code is less verbose. We also had to update the implementation code for fake expansions due to changes in the generate code (e.g., fake object is no longer exported). See https://github.com/kubernetes/kubernetes/pull/126503
• The webhook.Defaulter was removed from controller-runtime, and a custom webhook now needs to be provided. See https://github.com/kubernetes-sigs/controller-runtime/issues/2596.
• The Endpoints and EndpointSubset API types are officially deprecated as of K8s 1.33. For now, we silence golangci-lint deprecation warnings. In the future, we should remove usage of these types.