Indicate required on publish to people using screenreaders

This is a follow-up to #2986611: Indicate Require on Publish to User → which shows an indicator that there's something different about a field that is required on publish. Accessibility concerns were taken into account to ensure the icon for this wasn't distinguished only by color.

We should also indicate for people using screenreaders that a field is required on publish.

As there's no aria defined required-only-on-publish concept, i guess this would have to take the form of text that is given the visually-hidden class.

Alternatively/additionally, for our current use case we make nothing but the title regular required, so for us "required on publish" fully takes the place of regular required, and we make the required on publish fields use the usual red asterisk, and i would like to use aria-required="true" on the required on publish fields also if that would not be an accessibility faux pas.