feat(k8s): Switch from CoreV1 Endpoints to DiscoveryV1 EndpointSlice

[programmer04]

EndpointSlice API is available as V1 since K8s 1.21. Let's do not rely on old Endpoint API in KTF.

It's been spotted during work on Kong/kubernetes-ingress-controller#3916. In KIC TestCreateManager depends on this package. In that test K8s objects have to be mocked, relying on obsolete CoreV1 Endpoints by kubernetes-telemetry requires to use them in those mocks instead of DiscoveryV1 API.

[CLAassistant]

All committers have signed the CLA.

[czeslavo]

As for the mesh detection in telemetry, this looks good to me. 👍

I think we still have corev1.Endpoints usage in the reconcilers and parser though:
1) we ingest corev1.Endpoints via the reconciler https://github.com/Kong/kubernetes-ingress-~controller/blob/f42ca154c639dfd5ca4d34950cbc8b3b96113a82/internal/controllers/configuration/zz_generated_controllers.go#L186, putting this into the store
2) we fetch those from the store in the parser https://github.com/Kong/kubernetes-ingress-controller/blob/de7ba5c2446c2b14d09de38e68d707757f20637e/internal/dataplane/parser/parser.go#L703

We could merge this and tackle the above in a separate PR, WDYT?

[programmer04]

Yes @czeslavo I'm doing this step by step. Locally I have code with those changes mentioned by you. But firstly I want to merge Kong/kubernetes-ingress-controller#3964 and bump kubernetes-telemetry in KIC as separate PR

[czeslavo]

@programmer04 Oh oh, I just missed that this is not a PR to KIC 😅 Nevermind! :)