libpng: upgrade 1.6.42 -> 1.6.43

Changelog:
===========
-Fixed the row width check in png_check_IHDR().
-Added eXIf chunk support to the push-mode reader in pngpread.c.
-Added contrib/pngexif for the benefit of the users who would like
 to inspect the content of eXIf chunks.
-Added contrib/conftest/basic.dfa, a basic build-time configuration.
-Fixed a preprocessor condition in pngread.c that broke build-time
 configurations like contrib/conftest/pngcp.dfa.
-Added CMake build support for LoongArch LSX.
-Fixed a CMake build error that occurred under a peculiar state of the
 dependency tree. This was a regression introduced in libpng-1.6.41.
-Marked the installed libpng headers as system headers in CMake.
-Updated the build support for RISCOS.
-Updated the makefiles to allow cross-platform builds to initialize
 conventional make variables like AR and ARFLAGS.
-Added various improvements to the CI scripts in areas like version
  consistency verification and text linting.
Added version consistency verification to pngtest.c also.

(From OE-Core rev: d36edc338fde6879390c322fb6333812a2c2ed74)

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-multimedia/libpng/libpng_1.6.43.bb

@@ -10,8 +10,8 @@ DEPENDS = "zlib"
 
 LIBV = "16"
 
-SRC_URI = "${SOURCEFORGE_MIRROR}/project/${BPN}/${BPN}${LIBV}/${BP}.tar.xz"
-SRC_URI[sha256sum] = "c919dbc11f4c03b05aba3f8884d8eb7adfe3572ad228af972bb60057bdb48450"
+SRC_URI = "${SOURCEFORGE_MIRROR}/${BPN}/${BPN}${LIBV}/${BP}.tar.xz"
+SRC_URI[sha256sum] = "6a5ca0652392a2d7c9db2ae5b40210843c0bbc081cbd410825ab00cc59f14a6c"
 
 MIRRORS += "${SOURCEFORGE_MIRROR}/project/${BPN}/${BPN}${LIBV}/ ${SOURCEFORGE_MIRROR}/project/${BPN}/${BPN}${LIBV}/older-releases/"