♻️ Refactor user update (#689)

backend/app/crud.py

@@ -16,10 +16,7 @@ def create_user(*, session: Session, user_create: UserCreate) -> User:
     return db_obj
 
 
-def update_user(*, session: Session, user_id: int, user_in: UserUpdate) -> Any:
-    db_user = session.get(User, user_id)
-    if not db_user:
-        return None
+def update_user(*, session: Session, db_user: User, user_in: UserUpdate) -> Any:
     user_data = user_in.model_dump(exclude_unset=True)
     extra_data = {}
     if "password" in user_data: