Indicate that aria-grabbed and aria-dropeffect are deprecated

[scottaohara]

ARIA 1.1 deprecated aria-grabbed and aria-dropeffect. While no feature yet exists to replace these attributes, their current support is not particularly great, and since they are deprecated, it is highly unlikely their support will improve.

ARIA in HTML is being updated to call out that authors should not rely on these features, and request that conformance checkers warn authors about the attributes' deprecated status.

aria-grabbed and aria-dropeffect test case

[tombrunet]

Need to discuss with team what level deprecated features should be reported at. My gut feels like it should be a recommendation.

[aliunwala]

Agreement in triage into make this into a Recommendation

Also a helpful link:
https://www.w3.org/TR/wai-aria-1.2/#deprecated

[tombrunet]

Note: Create a rule where the attribute is tokenized with a list of deprecated attributes (Maybe look for a deprecated attribute in the ARIA spec file)

[shunguoy]

this is the related issue with #680, so is grouped in the same epic. Most likely, no additional work is needed. probably close as fixed with #680