[jfx17u] RFR: 8368572: Update WebKit to 623.1 [v2]

[Johan Vos]

> Hi all,
> 
> This pull request contains a backport of commit 422d3a95 from the openjdk/jfx repository.
> 
> The commit being backported was authored by Hima Bindu Meda on 21 Jan 2026 and was reviewed by Kevin Rushforth, Joeri Sykora and Johan Vos.
> 
> This PR also includes changes to modules/javafx.web/src/test/java/test/javafx/scene/web/LoadTest.java that are required because of the difference in junit versions between jfx17u and jfx
> 
> Thanks!

Johan Vos has updated the pull request incrementally with one additional commit since the last revision:

  Fix loadtest issues due to different junit versions

-------------

Changes:
  - all: https://git.openjdk.org/jfx17u/pull/256/files
  - new: https://git.openjdk.org/jfx17u/pull/256/files/b53304a7..08b92f9d

Webrevs:
 - full: Webrev is not available because diff is too large
 - incr: https://webrevs.openjdk.org/?repo=jfx17u&pr=256&range=00-01

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jfx17u/pull/256.diff
  Fetch: git fetch https://git.openjdk.org/jfx17u.git pull/256/head:pull/256

PR: https://git.openjdk.org/jfx17u/pull/256