Fix deprecation warning for Pydantic >=1.0

Author: StephenBrown2

{{cookiecutter.project_slug}}/backend/app/app/crud/base.py

@@ -41,7 +41,7 @@ def update(
         self, db_session: Session, *, db_obj: ModelType, obj_in: UpdateSchemaType
     ) -> ModelType:
         obj_data = jsonable_encoder(db_obj)
-        update_data = obj_in.dict(skip_defaults=True)
+        update_data = obj_in.dict(exclude_unset=True)
         for field in obj_data:
             if field in update_data:
                 setattr(db_obj, field, update_data[field])