Use fully-qualified module names for builtin Ansible modules

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

roles/matrix-nginx-proxy/tasks/self_check_well_known.yml

@@ -1,7 +1,7 @@
 ---
 
 - name: Determine well-known files to check (Matrix)
-  set_fact:
+  ansible.builtin.set_fact:
     well_known_file_checks:
       - path: /.well-known/matrix/client
         purpose: Client Discovery
@@ -10,7 +10,7 @@
         validate_certs: "{{ matrix_nginx_proxy_self_check_validate_certificates }}"
 
 - block:
-    - set_fact:
+    - ansible.builtin.set_fact:
         well_known_file_check_matrix_server:
           path: /.well-known/matrix/server
           purpose: Server Discovery
@@ -19,7 +19,7 @@
           validate_certs: "{{ matrix_nginx_proxy_self_check_validate_certificates }}"
 
     - name: Determine domains that we require certificates for (ma1sd)
-      set_fact:
+      ansible.builtin.set_fact:
         well_known_file_checks: "{{ well_known_file_checks + [well_known_file_check_matrix_server] }}"
   when: matrix_well_known_matrix_server_enabled|bool