fix part 2

backend/app/database/models/board.py

@@ -1,6 +1,6 @@
 """Board database model."""
 
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import TYPE_CHECKING
 from uuid import UUID, uuid4
 
@@ -42,9 +42,9 @@ class Board(Base):
         default=lambda: {"x": 0, "y": 0, "zoom": 1.0, "rotation": 0},
     )
 
-    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=datetime.utcnow)
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime, nullable=False, default=datetime.utcnow, onupdate=datetime.utcnow
+        DateTime, nullable=False, default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc)
     )
     is_deleted: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)