git: openjdk/jdk26u: master: 8377526: Update Libpng to 1.6.55

[Jayathirth D V]

Changeset: 4a51260a
Branch: master
Author:    Jayathirth D V <jdv at openjdk.org>
Date:      2026-02-26 12:16:50 +0000
URL:       https://git.openjdk.org/jdk26u/commit/4a51260aa999ba8236d5d0d50b3e823162e1d11e

8377526: Update Libpng to 1.6.55

Backport-of: fd74232d5dc4c6bfbcddb82e1b2621289aa2f65a

! src/java.desktop/share/legal/libpng.md
! src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
! src/java.desktop/share/native/libsplashscreen/libpng/README
! src/java.desktop/share/native/libsplashscreen/libpng/png.c
! src/java.desktop/share/native/libsplashscreen/libpng/png.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c