style: format code with Black and isort (#244)

This commit fixes the style issues introduced in 8527803 according to the output
from Black and isort.

Details: None

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

Author: deepsource-autofix[bot]

docs/src/class_based_views2.py

@@ -2,7 +2,7 @@
 from uuid import UUID
 
 import sqlalchemy as sa
-from fastapi import Depends, FastAPI, Header, HTTPException, APIRouter
+from fastapi import APIRouter, Depends, FastAPI, Header, HTTPException
 from sqlalchemy.orm import Session, declarative_base
 from starlette.status import HTTP_403_FORBIDDEN, HTTP_404_NOT_FOUND