Remove code examples for Python 3.8 in `response_directly`

docs/en/docs/advanced/custom-response.md

@@ -136,7 +136,7 @@ It accepts the following parameters:
 
 FastAPI (actually Starlette) will automatically include a Content-Length header. It will also include a Content-Type header, based on the `media_type` and appending a charset for text types.
 
-{* ../../docs_src/response_directly/tutorial002.py hl[1,18] *}
+{* ../../docs_src/response_directly/tutorial002_py39.py hl[1,18] *}
 
 ### `HTMLResponse` { #htmlresponse }
 

docs/en/docs/advanced/response-directly.md

@@ -54,7 +54,7 @@ Let's say that you want to return an <a href="https://en.wikipedia.org/wiki/XML"
 
 You could put your XML content in a string, put that in a `Response`, and return it:
 
-{* ../../docs_src/response_directly/tutorial002.py hl[1,18] *}
+{* ../../docs_src/response_directly/tutorial002_py39.py hl[1,18] *}
 
 ## Notes { #notes }
 

tests/test_tutorial/test_response_directly/test_tutorial001.py

@@ -9,7 +9,7 @@ from ...utils import needs_py310, needs_pydanticv1, needs_pydanticv2
 @pytest.fixture(
     name="client",
     params=[
-        pytest.param("tutorial001"),
+        pytest.param("tutorial001_py39"),
         pytest.param("tutorial001_py310", marks=needs_py310),
     ],
 )