Mark api._mixins.ARIAMixin__Element.ariaRelevant nonstandard (#10364)
Mark api._mixins.ARIAMixin__Element.ariaRelevant nonstandard (#10364)

ariaRelevant isn’t currently part of any spec. See
https://github.com/w3c/aria/issues/1267 for an issue about reinstating
it to the ARIA spec. But unless/until that change is actually made, we
should have it marked non-standard in BCD.
chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data