fix part 2

backend/app/database/models/image.py

@@ -1,6 +1,6 @@
 """Image database model."""
 
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import TYPE_CHECKING
 from uuid import UUID, uuid4
 
@@ -38,7 +38,7 @@ class Image(Base):
     height: Mapped[int] = mapped_column(Integer, nullable=False)
     image_metadata: Mapped[dict] = mapped_column(JSONB, nullable=False)
 
-    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))
     reference_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
 
     # Relationships