Another trip into the hell of dependencies: docutils tends to put major changes
in minor patches: the executables have been renamed / e.g.
rst2html.py --> rts2html
so we have to use docutils at least from version 0.21.2, but this version of
docutils is only supported by myst-parser from version 3.0.1 on.
Additionally, docutils decided to drop python 3.8 in version 0.21 [1]
Further, linuxdoc needed an update to cope with docutils 0.21 [2]
[1] https://docutils.sourceforge.io/RELEASE-NOTES.html#release-0-21-2024-04-09
[2] https://github.com/return42/linuxdoc/pull/36
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>