[4.2.x] Fixed #34428 -- Made ASGIStaticFilesHandler adapt response to async iterator.

Bug in 0bd2c0c901.
Backport of 02c356f2f3 from main

django/contrib/staticfiles/handlers.py

@@ -103,4 +103,13 @@ class ASGIStaticFilesHandler(StaticFilesHandlerMixin, ASGIHandler):
     async def get_response_async(self, request):
         response = await super().get_response_async(request)
         response._resource_closers.append(request.close)
+        # FileResponse is not async compatible.
+        if response.streaming and not response.is_async:
+            _iterator = response.streaming_content
+
+            async def awrapper():
+                for part in await sync_to_async(list)(_iterator):
+                    yield part
+
+            response.streaming_content = awrapper()
         return response

tests/asgi/tests.py

@@ -116,7 +116,6 @@ class ASGITest(SimpleTestCase):
             "django.contrib.staticfiles.finders.FileSystemFinder",
         ],
     )
-    @ignore_warnings(module="django.http.response")
     async def test_static_file_response(self):
         application = ASGIStaticFilesHandler(get_asgi_application())
         # Construct HTTP request.