chore: align cert-manager ready check with e2e tests (#953)

* chore: Align cert-manager ready check with e2e tests

Link: https://github.com/kubeflow/notebooks/blob/d76af839376385ee893ac666447a0ca1ed00e85d/workspaces/controller/test/utils/certmanager.go#L67-L73
Signed-off-by: Christian Heusel <christian@heusel.eu>

* chore: Remove usage of deprecated endpoint resource

When running the checks here the following warning was emitted:

    Warning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice

Fix this by migrating to the new `endpointslice` resource type.

Link: https://kubernetes.io/blog/2025/04/24/endpoints-deprecation/
Signed-off-by: Christian Heusel <christian@heusel.eu>

---------

Signed-off-by: Christian Heusel <christian@heusel.eu>

Author: christian-heusel

developing/scripts/setup-cert-manager.sh

@@ -24,9 +24,20 @@ kubectl wait --for=condition=ready pod \
   -n cert-manager \
   --timeout=120s
 
+kubectl wait deployment.apps --for condition=Available \
+  --selector app.kubernetes.io/instance=cert-manager \
+  --all-namespaces \
+  --timeout=120s
+
+kubectl wait endpointslice \
+  --for="jsonpath=endpoints[0].targetRef.kind=Pod" \
+  --selector app.kubernetes.io/instance=cert-manager \
+  --all-namespaces \
+  --timeout=120s
+
 # Also wait for the CRDs to be established
 kubectl wait --for=condition=established crd/certificates.cert-manager.io --timeout=60s
 kubectl wait --for=condition=established crd/issuers.cert-manager.io --timeout=60s
 kubectl wait --for=condition=established crd/clusterissuers.cert-manager.io --timeout=60s
 
-echo "Cert-manager setup complete"
+echo "Cert-manager setup complete"

workspaces/controller/test/utils/certmanager.go

@@ -79,8 +79,8 @@ func WaitCertManagerRunning() error {
 	// Wait for the cert-manager Endpoints to be ready
 	// NOTE: the webhooks will not function correctly until this is ready
 	cmd = exec.Command("kubectl", "wait",
-		"endpoints",
-		"--for", "jsonpath=subsets[0].addresses[0].targetRef.kind=Pod",
+		"endpointslice",
+		"--for", "jsonpath=endpoints[0].targetRef.kind=Pod",
 		"--selector", "app.kubernetes.io/instance=cert-manager",
 		"--all-namespaces",
 		"--timeout", "2m",