We don't support "is" content attribute. Consequently, we don't need to check for this attribute name in HTMLDocumentParserFastPath::scanAttributeName.
Pull request: https://github.com/WebKit/WebKit/pull/25084
Committed 275331@main (5590366d49ca): <https://commits.webkit.org/275331@main> Reviewed commits have been landed. Closing PR #25084 and removing active labels.
<rdar://problem/123641381>