Use fully-qualified module names for builtin Ansible modules

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1939

roles/matrix-coturn/tasks/validate_config.yml

@@ -1,7 +1,7 @@
 ---
 
 - name: Fail if required Coturn settings not defined
-  fail:
+  ansible.builtin.fail:
     msg: >-
       You need to define a required configuration setting (`{{ item }}`) for using Coturn.
   when: "vars[item] == ''"