Remove unused os import

Remove unused os module import from unity_connection.py as identified by CodeRabbit.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: sakurachan

MCPForUnity/UnityMcpServer~/src/unity_connection.py

@@ -4,7 +4,6 @@
 import errno
 import json
 import logging
-import os
 from pathlib import Path
 from port_discovery import PortDiscovery
 import random

Server/unity_connection.py

@@ -4,7 +4,6 @@
 import errno
 import json
 import logging
-import os
 from pathlib import Path
 from port_discovery import PortDiscovery
 import random