Use fully-qualified module names for builtin Ansible modules

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

roles/matrix-bridge-mautrix-whatsapp/tasks/validate_config.yml

@@ -1,7 +1,7 @@
 ---
 
 - name: Fail if required settings not defined
-  fail:
+  ansible.builtin.fail:
     msg: >-
       You need to define a required configuration setting (`{{ item }}`).
   when: "vars[item] == ''"
@@ -11,7 +11,7 @@
 
 
 - name: (Deprecation) Catch and report renamed settings
-  fail:
+  ansible.builtin.fail:
     msg: >-
       Your configuration contains a variable, which now has a different name.
       Please change your configuration to rename the variable (`{{ item.old }}` -> `{{ item.new }}`).