`context.propertySettings.cssCounterStyleAtRulesEnabled` can be used instead.
<rdar://problem/108725991>
Pull request: https://github.com/WebKit/WebKit/pull/13324
Committed 263547@main (f8114a261177): <https://commits.webkit.org/263547@main> Reviewed commits have been landed. Closing PR #13324 and removing active labels.