Update black, and run auto formatting over the codebase (#9381)

 - Update black version to the latest
 - Run black auto formatting over the codebase
    - Run autoformatting according to [`docs/code_style.md
`](https://github.com/matrix-org/synapse/blob/80d6dc9783aa80886a133756028984dbf8920168/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version

1 files changed, 2 insertions, 4 deletions

diff --git a/synapse/handlers/room_member_worker.py b/synapse/handlers/room_member_worker.py
index f2e88f6a5b..108730a7a1 100644
--- a/synapse/handlers/room_member_worker.py
+++ b/synapse/handlers/room_member_worker.py
@@ -44,8 +44,7 @@ class RoomMemberWorkerHandler(RoomMemberHandler):
         user: UserID,
         content: dict,
     ) -> Tuple[str, int]:
-        """Implements RoomMemberHandler._remote_join
-        """
+        """Implements RoomMemberHandler._remote_join"""
         if len(remote_room_hosts) == 0:
             raise SynapseError(404, "No known servers")
 
@@ -80,8 +79,7 @@ class RoomMemberWorkerHandler(RoomMemberHandler):
         return ret["event_id"], ret["stream_id"]
 
     async def _user_left_room(self, target: UserID, room_id: str) -> None:
-        """Implements RoomMemberHandler._user_left_room
-        """
+        """Implements RoomMemberHandler._user_left_room"""
         await self._notify_change_client(
             user_id=target.to_string(), room_id=room_id, change="left"
         )