Import tasks from other roles in a better way

One that doesn't trip up ansible-lint, causing `load-failure` errors.

roles/matrix-ma1sd/tasks/setup_install.yml

@@ -38,7 +38,9 @@
               systemd_services_to_stop: ['matrix-ma1sd.service']
               pgloader_options: ['--with "quote identifiers"']
 
-        - ansible.builtin.import_tasks: "{{ role_path }}/../matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+        - ansible.builtin.import_role:
+            name: matrix-postgres
+            tasks_from: migrate_db_to_postgres
 
         - ansible.builtin.set_fact:
             matrix_ma1sd_requires_restart: true