Use std::span in canUseSimplifiedTextMeasuringForCharacters().
Pull request: https://github.com/WebKit/WebKit/pull/19238
Committed 269491@main (1d59b86657c4): <https://commits.webkit.org/269491@main> Reviewed commits have been landed. Closing PR #19238 and removing active labels.
<rdar://problem/117173178>