[css-scroll-snap] Skip renderers with no element in updateSnapOffsetsForScrollableArea
rdar://111579277
Pull request: https://github.com/WebKit/WebKit/pull/19023
Committed 275523@main (2f88930ccc92): <https://commits.webkit.org/275523@main> Reviewed commits have been landed. Closing PR #19023 and removing active labels.