facts: get platform info from NetBox

Instead of pinging each host to see if it’s Windows. Make sure to set
the platform at least for such hosts.

setup.yml

@@ -1,19 +1,18 @@
 # common stuff
-- hosts: '*'
+- name: Get NetBox and other data
+  hosts: '*'
   gather_facts: false
   roles:
     - facts
 
-- hosts: '*'
+- name: Set up base system
+  hosts: '*'
   roles:
     - { role: alpine, when: ansible_distribution == 'Alpine' }
     - { role: debian, when: ansible_distribution == 'Debian' }
     - { role: windows, when: ansible_os_family == 'Windows' }
 
 # hosts
-- hosts: mgmt-gw
-  roles:
-
 - hosts: ceph-*
   roles:
     - frr