This was introduced when we started passing extensions an CBOR. We do the right thing for registerations, but not assertions.
rdar://95618710
Pull request: https://github.com/WebKit/WebKit/pull/1655
Committed r295702 (251707@main): <https://commits.webkit.org/251707@main> Reviewed commits have been landed. Closing PR #1655 and removing active labels.