flux:modal: Hide body scrollbar when modal is opened

[BubeDameKoenig]

If you open a flux:modal and the page has a scrollbar, this leads to strange user handling.
It becomes very strange if it is a flyout and it is longer. So there are two scrollbars next to each other.

Here in Github the body scrollbar is hidden.

Alpine suggestion:

x-init="$watch('show', value => {
      if (value) {
          document.body.classList.add('overflow-y-hidden');
      } else {
          document.body.classList.remove('overflow-y-hidden');
      }
  })"