Correct mysql_connections()

Author: adamchainz

src/django_mysql/utils.py

@@ -179,7 +179,7 @@ def get_list_sql(sequence: list[str] | tuple[str, ...]) -> str:
     return "({})".format(",".join("%s" for x in sequence))
 
 
-def mysql_connections() -> Generator[[str, BaseDatabaseWrapper]]:
+def mysql_connections() -> Generator[tuple[str, BaseDatabaseWrapper]]:
     conn_names = [DEFAULT_DB_ALIAS] + list(set(connections) - {DEFAULT_DB_ALIAS})
     for alias in conn_names:
         connection = connections[alias]