libxml2: Update to version 2.14.3

libxml2: Update to version 2.14.3

- Update from version 2.14.2 to 2.14.3
- Update of rootfile
- Changelog
    2.14.3
	### Regressions
		- reader: Fix reading compressed data
		- parser: Make undeclared entities in XML content fatal
		- save: Fix XML escape table
		- save: Fix xmlSave with NULL encoding
		- Revert "valid: Remove duplicate error messages when streaming"
	### Bug fixes
		- save: Fix serialization of attribute defaults containing <
		- io: Fix linkage of __xml*BufferCreateFilename functions
	### Build systems
		- cmake: Fix installation directories in libxml2-config.cmake
		- meson: Install libxml2.py
	### Improvements
		- parser: Make xmlCtxtGetValidCtxt depend on VALID_ENABLED
		- html: Avoid HTML_PARSE_HTML5 clashing with XML_PARSE_NOENT

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