r/system-auth: Remove uninstall authconfig task

The *authconfig* package has been gone from Fedora since ages.  There's
no reason to have this no-op step any more, especially since it has the
side-effect of making a network request to refresh the dnf cache.

roles/system-auth/tasks/main.yml

@@ -5,10 +5,6 @@
   - '{{ ansible_os_family }}.yml'
   - defaults.yml
 
-- name: ensure authconfig is not installed
-  package:
-    name=authconfig
-    state=absent
 - name: ensure authconfig PAM configuration is reset
   command:
     mv /etc/pam.d/{{ item }}-ac /etc/pam.d/{{ item }}