should add role="presentation" on the surrounding li

In the example usage on the [website](https://davidtheclark.github.io/react-aria-menubutton/demo/) and the [example ](https://github.com/davidtheclark/react-aria-menubutton/blob/master/demo/js/basicDemo.js)as part of the repo, the li which contains the `menuitem` does not have its semantics hidden (using role=presnetation or role=none). Which means for a screenreader user this is extra info which doesn't make sense semantically ?

Would it be better to add role="presentation" on these wrapper `li`s

This is also suggested on the [WAI ARIA pattern](https://www.w3.org/TR/wai-aria-practices/examples/menu-button/menu-button-links.html#:~:text=Hides%20the%20implied%20listitem%20role%20of%20the%20li%20element%20from%20assistive%20technologies.)

Inspect demo/js/basicDemo.js and the linked website example, then compare their menuitem wrapper li elements with the referenced WAI-ARIA menu-button pattern. Done means the surrounding li semantics are hidden with the requested presentation or none role in the affected examples.

Written by the indexing model from the issue text.