Reorganize imports in UserEntity for clarity

- Moved import statements for Pydantic to the top of the UserEntity file to enhance readability and maintainability.

Author: Dopeamin

src/corbado_python_sdk/entities/user_entity.py

@@ -1,6 +1,7 @@
-from pydantic import BaseModel, ConfigDict, Field, StrictStr
 from typing import Optional
 
+from pydantic import BaseModel, ConfigDict, Field, StrictStr
+
 from corbado_python_sdk.generated.models.user import User
 from corbado_python_sdk.generated.models.user_status import UserStatus