Disable automatic user creation when MAS migration is in progress

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3647

roles/custom/matrix-user-creator/tasks/setup.yml

@@ -31,7 +31,7 @@
       # Suppress logging to avoid dumping the credentials to the shell
       no_log: true
 
-- when: matrix_authentication_service_enabled | bool
+- when: matrix_authentication_service_enabled and not matrix_authentication_service_migration_in_progress
   block:
     - name: Ensure Matrix Authentication Service is started before creating Matrix users
       ansible.builtin.service: