Sub-task of rdar://124008411 (WKWebViewConfiguration ivars need to move to API::PageConfiguration)
<rdar://problem/124115170>
Pull request: https://github.com/WebKit/WebKit/pull/25520
Committed 275929@main (19739c622738): <https://commits.webkit.org/275929@main> Reviewed commits have been landed. Closing PR #25520 and removing active labels.