Always hide active menu item's navigation on mobile

The feature

#2991056 by Neslee Canil Pinto, rokzabukovec, inge_dt, adriancid: Always hide active menu item's navigation on mobile
https://www.drupal.org/node/2991056 →

This hide the vertical menu on mobile, but the code do this on the desktop too :

     // Always hide the dropdown menu on mobile.
      if ($('#toolbar-item-administration-tray').hasClass('toolbar-tray-vertical')) {
        $('#toolbar-item-administration').removeClass('is-active');
        $('#toolbar-item-administration-tray').removeClass('is-active');
      };

Step to reproduce :

Go to content
change the admin menu to vertical mode
Refresh the page

You ll see a white left col

Test on Drupal 8.9.6