Rebase to webkitgtk 2.52.5 (WebKitGTK Security Advisory WSA-2026-0004),
aligning with the 2.52.x security baseline shipped by RHEL 9
(RHSA-2026:42062).
Drop fix-system-malloc-llint-extractor.patch; the upstream cherry-pick
(WebKit 314364@main) is now included in 2.52.5.
Refresh libsoup2.patch for the 2.52.5 library version triplet bumps
(WEBKIT 21/9/21, JAVASCRIPTCORE 10/13/10 on API 4.1;
WEBKIT 20/9/16, JAVASCRIPTCORE 8/13/7 on API 6.0). The webkit2gtk-4.0
SONAME (libwebkit2gtk-4.0.so.37) is preserved.