text-decoration-skip can share the serialization handling with other shorthands with single longhands. We don't ever need to serialize `ink` because it gets changed to `auto` anyway at parse-time. We also don't need to take care of implicit property references, since we never add text-decoration-skip-ink as implicit in `consumeTextDecorationSkip()`.
<rdar://problem/102708232>
Pull request: https://github.com/WebKit/WebKit/pull/6851
Committed 257067@main (b564ed1fb7d6): <https://commits.webkit.org/257067@main> Reviewed commits have been landed. Closing PR #6851 and removing active labels.