Chip: on the web every Chip sets aria-selected on role button #5180

Current behaviour

On the web, every Chip renders <button role="button" aria-selected="true|false"> (Chip.tsx passes aria-selected={selected}, and selected defaults to false). aria-selected is not allowed on role button, so screen readers ignore the selected state, and axe-core reports aria-allowed-attr (critical): "ARIA attribute is not allowed: aria-selected". The example app shows it on the Chip, Card, Floating Action Button, List.Section and Tooltip screens.

Expected behaviour

On the web a Chip used as a toggle exposes its state with aria-pressed, the state role button supports, and only when the app passes selected, so a plain action chip isn't announced as a toggle. Native keeps announcing the selected state as it does today. axe reports no aria-allowed-attr violation.

How to reproduce?

1. Run the example app on the web from main (yarn install, then npx expo start --web in example/).
2. Open the Chip example (/chip).
3. Run axe-core on the page (for example with the axe DevTools extension).

Preview

What have you tried so far?

Your Environment