libunistring: Update to version 1.4.2

libunistring: Update to version 1.4.2

- Update from version 1.3 to 1.4.2
- Update of rootfile
- Changelog
1.4.2
* Fixed a build failure on systems with glibc 2.43.
1.4.1
* Fixed a compilation error in C++ mode.
1.4
* The data tables and algorithms have been updated to Unicode version 17.0.0.
* Fixed a bug: The functions u*_grapheme_next and u*_grapheme_prev did not
  work right for strings with Indic characters, Emojis, or regional indicators.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>