fix: datetime tz lint

Author: rushilpatel0

src/codegen/agents/data.py

@@ -1,15 +1,14 @@
 from dataclasses import dataclass, field
-from datetime import datetime
 from typing import Literal, Optional, Union
-
+from datetime import datetime, UTC
 
 # Base dataclass for all message types
 @dataclass
 class BaseMessage:
     """Base class for all message types."""
 
     type: str
-    timestamp: str = field(default_factory=lambda: datetime.now().isoformat())
+    timestamp: str = field(default_factory=lambda: datetime.now(tz=UTC).isoformat())
     content: str = ""