✨ Add support for function return type annotations to declare the response_model (#1436)

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

tests/test_reponse_set_reponse_code_empty.py

@@ -9,6 +9,7 @@ app = FastAPI()
 @app.delete(
     "/{id}",
     status_code=204,
+    response_model=None,
 )
 async def delete_deployment(
     id: int,