[UnifiedPDF] Use std::optional::transform() in enqueueTilePaintIfNecessary

[aprotyas]

59b7185

[UnifiedPDF] Use std::optional::transform() in enqueueTilePaintIfNecessary
https://bugs.webkit.org/show_bug.cgi?id=277985
rdar://133719325

Reviewed by Tim Horton.

We essentially hand-write `std::optional::transform()` in 282135@main, so
this patch just migrates to using the standard library version instead.

* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/AsyncPDFRenderer.mm:
(WebKit::AsyncPDFRenderer::enqueueTilePaintIfNecessary):

Canonical link: https://commits.webkit.org/282154@main

3cffe10

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	✅ 🧪 wincairo-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt		✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	❌ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	❌ 🧪 api-gtk
	✅ 🧪 vision-wk2
✅ 🛠 🧪 unsafe-merge	🛠 tv
	✅ 🛠 tv-sim
	✅ 🛠 watch
	🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 3cffe10)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2	✅ 🧪 wincairo-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt		✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	❌ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	❌ 🧪 api-gtk
	✅ 🧪 vision-wk2
✅ 🛠 🧪 unsafe-merge	🛠 tv
	✅ 🛠 tv-sim
	✅ 🛠 watch
	🛠 watch-sim

[aprotyas]

Test failures are unrelated. Thanks for the review!

[webkit-commit-queue]

Committed 282154@main (59b7185): https://commits.webkit.org/282154@main

Reviewed commits have been landed. Closing PR #32073 and removing active labels.