Review deprecation processes for ARIA attributes (and roles?)

[smhigley]

Semi-related to #1862

We have logic in aria.js to apply ARIA 1.2-specific deprecation warnings, but no other built-in deprecation language or system, particularly for deprecating support for an attribute on a role rather than deprecating the entire attribute/role.

TODOs:

• Figure out anything we need to do to align with other specs
• Set specific requirements around what should be deprecated vs. just removed
• Set wording/formatting for deprecation notice
• Add script for inserting the deprecation wording?

[jnurthen]

Discussed at ARIA meeting - https://www.w3.org/2023/02/02-aria-minutes#t05

[pkra]

Related: #80 asking if role=presentation should be deprecated. Though the minutes linked above mention that the group decided against deprecation (and for synonyms).

[spectranaut]

I'm running into this issue once again, with the deprecation of aria-atomic

I'd like for deprecated attributes (like aria-dropeffect and aria-atomic) to show up with (deprecated) in the list of supported attributes. For example, you can see the aria-dropeffect and aria-atomic listed in the alert inherited states and properties: https://w3c.github.io/aria/#alert

I think this is blocked on: #2408

[spectranaut]

Honestly, as we get more deprecate attributes, maybe it would be nice to make their own section instead of interleaving them with the other Inherited States and Properties

[pkra]

@spectranaut now that I've done my other tasks, I'm working up the courage to get back on #2408 🤞