Download coredns image to all hosts in k8s_cluster (#9316)

Coredns image must be available everywhere as it
may be rescheduled to a non-control-plane-node.

roles/download/defaults/main.yml

@@ -1411,7 +1411,7 @@ downloads:
     tag: "{{ coredns_image_tag }}"
     sha256: "{{ coredns_digest_checksum|default(None) }}"
     groups:
-    - kube_control_plane
+    - k8s_cluster
 
   nodelocaldns:
     enabled: "{{ enable_nodelocaldns }}"