Fix some ansible-lint-reported warnings

roles/matrix-postgres/tasks/import_generic_sqlite_db.yml

@@ -28,7 +28,8 @@
 - when: 'postgres_connection_string_variable_name is defined'
   block:
     - name: Fail if postgres_connection_string_variable_name points to an undefined variable
-      ansible.builtin.fail: msg="postgres_connection_string_variable_name is defined, but there is no variable with the name `{{ postgres_connection_string_variable_name }}`"
+      ansible.builtin.fail:
+        msg: "postgres_connection_string_variable_name is defined, but there is no variable with the name `{{ postgres_connection_string_variable_name }}`"
       when: "postgres_connection_string_variable_name not in vars"
 
     - name: Get Postgres connection string from variable

roles/matrix-postgres/tasks/run_vacuum.yml

@@ -82,7 +82,8 @@
   changed_when: matrix_postgres_synapse_vacuum_result.finished and matrix_postgres_synapse_vacuum_result.rc == 0
 
 # Intentionally show the results
-- ansible.builtin.debug: var="matrix_postgres_synapse_vacuum_result"
+- ansible.builtin.debug:
+    var: "matrix_postgres_synapse_vacuum_result"
 
 - name: Ensure matrix-synapse is started, if it previously was
   ansible.builtin.service: