m/n/k/nfproxy: use discovery/v1 API

The old discovery/v1beta1 is deprecated and removed in 1.25. We need to
get nfproxy to use the new API (available since 1.21) before we jump
to a K8s control plane version above 1.25.

Change-Id: I6336e168e9efbfc4a7b41f6fe15efebf95624df2
Reviewed-on: https://review.monogon.dev/c/monogon/+/2407
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/metropolis/node/kubernetes/nfproxy/nfproxy.go b/metropolis/node/kubernetes/nfproxy/nfproxy.go
index c07b291..637be7b 100644
--- a/metropolis/node/kubernetes/nfproxy/nfproxy.go
+++ b/metropolis/node/kubernetes/nfproxy/nfproxy.go
@@ -91,7 +91,7 @@
 			options.LabelSelector = labelSelector.String()
 		}))
 
-	endpointSlicesInformer := kubeInformerFactory.Discovery().V1beta1().EndpointSlices()
+	endpointSlicesInformer := kubeInformerFactory.Discovery().V1().EndpointSlices()
 	endpointSlicesInformer.Informer().SetWatchErrorHandler(func(_ *cache.Reflector, err error) {
 		supervisor.Logger(ctx).Errorf("endpoint slices watch error: %v", err)
 	})