ci: Avoid ansible_virtualization_type to check for docker targets

It's not consistant across Ansible versions, particular the oldest ones. This
may have contributed to older test images containing usernames from the host
OS that they were built on (e.g. dmw, alex).

tests/image_prep/_container_setup.yml

@@ -13,11 +13,6 @@
   vars:
     distro: "{{ansible_distribution}}"
 
-  pre_tasks:
-    - meta: end_play
-      when:
-        - ansible_virtualization_type != "docker"
-
   roles:
     - role: package_manager
     - role: packages

tests/image_prep/_user_accounts.yml

@@ -181,6 +181,6 @@
           {% endfor %}
         validate: '/usr/sbin/visudo -cf %s'
       when:
-        - ansible_virtualization_type != "docker"
+        - ansible_connection == "local"
   roles:
     - role: user_policies