[field] data-focused attribute persists when data-disabled

# Bug report / Feature request

With native HTML `` and ``, the elements are not focusable when disabled. Arguably, the same behavior should be reflected in the Base UI form components like `Field`, `Input`, `Select`, `Autocomplete`, `Combobox`, etc. This could be achieved by removing `data-focused` when `data-disabled` is added.

The current Tailwind workaround is to use a `not-data-disabled:data-focused: ...` modifier, or `focus-visible: ...` in cases where that would actually work instead. However, I don't think this is something consumers should have to implement. I don't think users expect `data-focused` to persist when `data-disabled`.

I do like that the `Button` component has the `focusableWhenDisabled` prop and it correctly defaults to `false`. This could be added to the form-related components, but I don't think there's a strong need. The primary issue is simply the persistence of `data-focused`.

Thanks for your help.