Remove the "nova-network" from the ansible

The nova-network was deprecated, this patch to remove it
from the ansible role
TrivialFix

Change-Id: I6ea9b007a55317e36c6f5117781f9c3ed36b0012

ansible/roles/nova/templates/nova-network.json.j2

-{
-    "command": "nova-network",
-    "config_files": [
-        {
-            "source": "{{ container_config_directory }}/nova.conf",
-            "dest": "/etc/nova/nova.conf",
-            "owner": "nova",
-            "perm": "0600"
-        }
-    ]
-}

releasenotes/notes/remove-nova-network-76e1c9b51a4acd5f.yaml

+---
+deprecations:
+  - The nova-network was deprecated, we remove it from the nova ansible
+    role.
+