Warnings about non supported, non global ARIA attributes use on ARIA roles

[spectranaut]

ARIA is dropping support of aria-expanded on role listbox: w3c/aria#1862

This means the following HTML is no longer valid:

<div role="listbox" aria-label="foo" aria-expanded="true">
</div>

I noticed, however, that vnu does not raised any errors when a non-supported, non global ARIA attribute is used on a role. For example, the following does not raise an error:

<div role="heading" aria-rowspan="3" id="oops" aria-expanded="true">
</div>