aria-required-children's reviewEmpty option is broken on hidden children

[WilcoFiers]

The following should be reported as incomplete of aria-required-children, rather than as a violation:

<div role="menu">
  <a href="#" role="menuitem" hidden>foo</a>
</div>

This bug was introduced in #3949, which told axe to ignore the roles of hidden children, but doesn't ignore hidden children when checking reviewEmpty.