Fix flakiness

Author: compulim

__tests__/html2/part-grouping/index.html

@@ -417,6 +417,7 @@
 
       // Then: show the closing message after the list
       await pageConditions.numActivitiesShown(6);
+      await pageConditions.scrollToBottomCompleted();
       await host.snapshot('local');
     });
   </script>