Remove really old cruft from instackenv.json.j2

Nothing except for "nodes" list is used right now.

Also remove references to nova-baremetal, it was deprecated in Juno (?).

Change-Id: Ibfcdf9b5a6ba8829e9a167a697182c5d4d207efe

roles/libvirt/defaults/main.yml

@@ -19,9 +19,6 @@ images:
       url: "{{ undercloud_image_url }}"
       type: qcow2
 
-# Which power manager should we use?
-nova_power_manager: 'nova.virt.baremetal.virtual_power_driver.VirtualPowerManager'
-
 # These are keys that we generate; `virt_power_key` is used *by the
 # undercloud* to start/stop virtual machines on the virthost.
 # `undercloud_key` is used to log in to the undercloud.

roles/libvirt/setup/overcloud/templates/instackenv.json.j2

@@ -24,10 +24,4 @@
     {% endif %}
   {% endfor %}
   ],
-  "arch": "{{ libvirt_arch }}",
-  "host-ip": "{{ host_ip }}",
-  "power_manager": "{{ nova_power_manager }}",
-  "seed-ip": "",
-  "ssh-key": {{ virt_power_key_pvt | to_nice_json }},
-  "ssh-user": "{{ ansible_user_id }}"
 }