python3-lxml: upgrade 4.9.3 -> 4.9.4

python3-lxml: upgrade 4.9.3 -> 4.9.4

Changelog:
===========
* LP#2046398: Inserting/replacing an ancestor into a node's children could loop indefinitely.
* LP#1980767, GH#379: "TreeBuilder.close()" could fail with a "TypeError" after
  parsing incorrect input.
* LP#1522052: A file-system specific test is now optional and should no longer fail
  on systems that don't support it.
* Wheels include zlib 1.3, libxml2 2.10.3 and libxslt 1.1.39
  (zlib 1.2.12, libxml2 2.10.3 and libxslt 1.1.37 on Windows).
* Built with Cython 0.29.37.

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