- update to 4.12.3:
* Fixed a regression such that if you set .hidden on a tag, the
tag becomes invisible but its contents are still visible. User
manipulation of .hidden is not a documented or supported
feature, so don't do this, but it wasn't too difficult to
keep the old behavior
working.
* Fixed a case found by Mengyuhan where html.parser giving up
on markup would result in an AssertionError instead of a
ParserRejectedMarkup exception.
* Added the correct stacklevel to instances of the
XMLParsedAsHTMLWarning.
* Corrected the syntax of the license definition in
pyproject.toml.
* Corrected a typo in a test that was causing test failures
when run against libxml2 2.12.1.

- Require cchardet explicitly to avoid charset-normalizer braindamage.
- disable tests on SLE_11, fail due to too old python-lxml
- remove lxml support (fails unit test)
- Use recommended lxml parser instead of native one