roles/mariadb: use socket for all operations

Otherwise Ansible will try to connect with host 'localhost', which
we do not use (and we have disabled name resolution anyways).

roles/mariadb/tasks/main.yml

@@ -43,13 +43,13 @@
 
 # See: https://docs.ansible.com/ansible/latest/collections/community/mysql/mysql_db_module.html
 - name: Create MariaDB database(s)
-  mysql_db: db={{ item.name }} state=present encoding=utf8mb4
+  mysql_db: db={{ item.name }} state=present encoding=utf8mb4 login_unix_socket={{ mariadb_login_unix_socket }}
   loop: "{{ mariadb_databases }}"
   when: mariadb_databases is defined
   tags: mariadb
 
 - name: Create MariaDB user(s)
-  mysql_user: name={{ item.user }} password={{ item.pass }} priv={{ item.name }}.*:ALL host=127.0.0.1 state=present
+  mysql_user: name={{ item.user }} password={{ item.pass }} priv={{ item.name }}.*:ALL host=127.0.0.1 state=present login_unix_socket={{ mariadb_login_unix_socket }}
   loop: "{{ mariadb_databases }}"
   when: mariadb_databases is defined
   tags: mariadb