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
`](80d6dc9783/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version

synapse/replication/tcp/redis.py

@@ -123,8 +123,7 @@ class RedisSubscriber(txredisapi.SubscriberProtocol, AbstractConnection):
         self.synapse_handler.send_positions_to_connection(self)
 
     def messageReceived(self, pattern: str, channel: str, message: str):
-        """Received a message from redis.
-        """
+        """Received a message from redis."""
         with PreserveLoggingContext(self._logging_context):
             self._parse_and_dispatch_message(message)
 
@@ -137,7 +136,8 @@ class RedisSubscriber(txredisapi.SubscriberProtocol, AbstractConnection):
             cmd = parse_command_from_line(message)
         except Exception:
             logger.exception(
-                "Failed to parse replication line: %r", message,
+                "Failed to parse replication line: %r",
+                message,
             )
             return