sideways writing modes use the horizontal typographic mode, which disables text-combine-upright.
<rdar://problem/113703767>
Pull request: https://github.com/WebKit/WebKit/pull/16577
Committed 266792@main (6f0a9e880a3f): <https://commits.webkit.org/266792@main> Reviewed commits have been landed. Closing PR #16577 and removing active labels.