✨ Add support for Trio via AnyIO (#3372)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

docs_src/async_tests/test_main.py

@@ -4,7 +4,7 @@ from httpx import AsyncClient
 from .main import app
 
 
-@pytest.mark.asyncio
+@pytest.mark.anyio
 async def test_root():
     async with AsyncClient(app=app, base_url="http://test") as ac:
         response = await ac.get("/")