fix: remove unused mypy ignore type comments (#1769)

Author: zimeg

slack_sdk/socket_mode/websocket_client/__init__.py

@@ -11,7 +11,7 @@
 from logging import Logger
 from queue import Queue
 from threading import Lock
-from typing import Union, Optional, List, Callable, Tuple
+from typing import Callable, List, Optional, Tuple, Union
 
 import websocket
 from websocket import WebSocketApp, WebSocketException
@@ -180,10 +180,10 @@ def on_close(
 
         self.current_session = websocket.WebSocketApp(
             self.wss_uri,
-            on_open=on_open,  # type: ignore[arg-type]
-            on_message=on_message,  # type: ignore[arg-type]
-            on_error=on_error,  # type: ignore[arg-type]
-            on_close=on_close,  # type: ignore[arg-type]
+            on_open=on_open,
+            on_message=on_message,
+            on_error=on_error,
+            on_close=on_close,
         )
         self.auto_reconnect_enabled = self.default_auto_reconnect_enabled