Fix black formatting in test_aiohttp_multipart.py

Co-Authored-By: Claude <noreply@anthropic.com>

Author: magicmark

tests/test_aiohttp_multipart.py

@@ -488,11 +488,7 @@ async def test_aiohttp_multipart_empty_content_type_skipped(multipart_server):
     book1_payload = json.dumps({"payload": {"data": {"book": book1}}})
 
     parts = [
-        (
-            "--graphql\r\n"
-            "\r\n"
-            "\r\n"
-        ),
+        ("--graphql\r\n" "\r\n" "\r\n"),
         (
             "--graphql\r\n"
             "Content-Type: application/json\r\n"