cleanup imports

ml-agents-envs/mlagents_envs/side_channel/engine_configuration_channel.py

-from mlagents_envs.side_channel.side_channel import (
-    SideChannel,
-    OutgoingMessage,
-    IncomingMessage,
-)
+from mlagents_envs.side_channel import SideChannel, OutgoingMessage, IncomingMessage
 from mlagents_envs.exception import UnityCommunicationException
 import uuid
 from typing import NamedTuple

ml-agents-envs/mlagents_envs/side_channel/float_properties_channel.py

-from mlagents_envs.side_channel.side_channel import (
-    SideChannel,
-    IncomingMessage,
-    OutgoingMessage,
-)
+from mlagents_envs.side_channel import SideChannel, IncomingMessage, OutgoingMessage
 import uuid
 from typing import Dict, Optional, List
 

ml-agents-envs/mlagents_envs/side_channel/raw_bytes_channel.py

-from mlagents_envs.side_channel.side_channel import (
-    SideChannel,
-    IncomingMessage,
-    OutgoingMessage,
-)
+from mlagents_envs.side_channel import SideChannel, IncomingMessage, OutgoingMessage
 from typing import List
 import uuid