Refactor import path for app_config

Updated import statement to use a relative path.

Author: NirajC-Microsoft

src/backend/v3/magentic_agents/models/agent_models.py

@@ -3,7 +3,7 @@
 import os
 from dataclasses import dataclass
 
-from src.backend.common.config.app_config import config
+from common.config.app_config import config
 
 
 @dataclass(slots=True)