git: openjdk/jdk11u-dev: 8316030: Update Libpng to 1.6.40

[Andrew Lu]

Changeset: 8191f621
Author:    Andrew Lu <andrewlu at openjdk.org>
Date:      2023-12-07 01:54:06 +0000
URL:       https://git.openjdk.org/jdk11u-dev/commit/8191f621993f5c271e31d18aa385333e39d6a919

8316030: Update Libpng to 1.6.40

Backport-of: 158293d2517695f8c5eaca1b46ecf0f1f9f09691

! src/java.desktop/share/legal/libpng.md
! src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
! src/java.desktop/share/native/libsplashscreen/libpng/LICENSE
! 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/pngget.c
! src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngset.c