libcpp, contrib: Update to Unicode 15.1

The following patch (in plaintext just a pseudo-patch where I've left out
the too big parts of either wget downloaded or regenerated files out with
..., full patch attached compressed) updates to Unicode 15.1 from 15.0
we had last year.  Apparently Unicode forgot to add a new range to 4-8 Table
we are using, but from the other files it is clear what should have been
added; I've filed a bugreport against Unicode.

2023-11-14  Jakub Jelinek  <jakub@redhat.com>

contrib/
	* unicode/README: Adjust glibc git commit hash, number of Unicode
	data files to be updated and latest Unicode version.
	* unicode/from_glibc/utf8_gen.py: Update from glibc.
	* unicode/UnicodeData.txt: Update from Unicode 15.1.
	* unicode/EastAsianWidth.txt: Likewise.
	* unicode/DerivedNormalizationProps.txt: Likewise.
	* unicode/NameAliases.txt: Likewise.
	* unicode/DerivedCoreProperties.txt: Likewise.
	* unicode/PropList.txt: Likewise.
libcpp/
	* makeucnid.cc (write_copyright): Update copyright year.
	* makeuname2c.cc (write_copyright): Likewise.
	(struct generated): Update latest Unicode version.
	(generated_ranges): Add 2ebf0-2ee5d CJK UNIFIED IDEOGRAPH
	range which was forgotten to be added to 4-8 table, but
	clearly is expected to be there from the 15.1 additions.
	* ucnid.h: Regenerated.
	* uname2c.h: Regenerated.
	* generated_cpp_wcwidth.h: Regenerated.