Update kindest/node Docker tag to v1.28.15

Author: renovate[bot]

hack/config/kind-config.yaml

@@ -2,7 +2,7 @@ apiVersion: kind.x-k8s.io/v1alpha4
 kind: Cluster
 nodes:
 - role: control-plane
-  image: kindest/node:v1.28.13
+  image: kindest/node:v1.28.15
   extraPortMappings:
   # ingress-nginx
   - containerPort: 30888