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/text_to_speech/tts.py

@@ -1,8 +1,9 @@
 import asyncio
 import re
+from collections.abc import AsyncGenerator, Generator
 from dataclasses import dataclass
 from functools import lru_cache
-from typing import AsyncGenerator, Generator, Literal, Protocol, TypeVar
+from typing import Literal, Protocol, TypeVar
 
 import numpy as np
 from huggingface_hub import hf_hub_download