mypy fixes

src/baby_monitor/models/db/user.py

@@ -1,9 +1,14 @@
 """Database models."""
 
+from typing import TYPE_CHECKING
 from sqlalchemy import Column, Integer, String, DateTime, Boolean
 from datetime import datetime
 
-from baby_monitor.repositories.dependencies.get_database import Base
+if TYPE_CHECKING:
+    from sqlalchemy.orm import DeclarativeBase
+    Base = DeclarativeBase
+else:
+    from baby_monitor.repositories.dependencies.get_database import Base
 
 
 class User(Base):