Enforce modern typing (#258)

* Allow UP

* Upgrade typing

* test smolagents

* Change to contextlib

---------

Co-authored-by: Marcus Valtonen Örnhag <marcus.valtonen.ornhag@ericsson.com>

backend/fastrtc/webrtc_connection_mixin.py

@@ -6,10 +6,9 @@ import asyncio
 import inspect
 import logging
 from collections import defaultdict
-from collections.abc import Callable
+from collections.abc import AsyncGenerator, Callable
 from dataclasses import dataclass, field
 from typing import (
-    AsyncGenerator,
     Literal,
     ParamSpec,
     TypeVar,