fixup! Fix `NoneType` return type for 204 endpoints

fastapi/dependencies/utils.py

@@ -278,8 +278,7 @@ def get_typed_return_annotation(call: Callable[..., Any]) -> Any:
     globalns = getattr(call, "__globals__", {})
     typed_annotation = get_typed_annotation(annotation, globalns)
 
-    NoneType = type(None)
-    if issubclass(typed_annotation, NoneType):
+    if typed_annotation is type(None): # noqa: E721
         return None
 
     return typed_annotation