another try at fixing resource warnings

Author: kumaraditya303

Lib/test/test_asyncio/test_subprocess.py

@@ -558,9 +558,7 @@ async def cancel_make_transport():
         # "Exception during subprocess creation, kill the subprocess"
         with test_utils.disable_logger():
             self.loop.run_until_complete(cancel_make_transport())
-            test_utils.run_briefly(self.loop)
-            test_utils.run_briefly(self.loop)
-            test_utils.run_briefly(self.loop)
+            self.loop.run_until_complete(asyncio.sleep(0.1))
 
     def test_close_kill_running(self):