I want to:

- remove old cython recipe
- remove 3.9 package.

Stuff that needs Cython:

[x] borgbackup - 3.10
[ ] libplist (doesn't specify which Python version
[x] lxml (uses "--without-cython")
[x] multidict - 3.10
[ ] numpy - 3.9/3.10 - recipe needs cleanup.
[ ] pandas - 3.9 -> move to 3.10 / update if possible. (nothing uses it)
[ ] pyenet - 3.9/3.10 - recipe needs cleanup.
	should at least drop pyenet 3.9
	only used by "unkown_horizons", "cmd:python" !!!
	newer unkown_horizons doesn't even uses pyenet, is being ported to godot, and declared "dead".
[x] pygame - 3.10
[ ] pyzmq - 3.9/3.10 - recipe needs cleanup.
	only 3.10 needed (openshot)
[ ] sphinx - 3.9/3.10 (only use 3.10? it is a cmd: after all)
	- sphinx_argparse - 3.9/3.10
	- sphinx_rtd_theme - 3.9/3.10
		- assimp_docs - 3.10 (why the hell do we even have this on-tree?)
	- sphinxcontrib_applehelp - 3.9/3.10
	- sphinxcontrib_devhelp - 3.9/3.10
	- sphinxcontrib_htmlhelp - 3.9/3.10
	- sphinxcontrib_jquery - 3.9/3.10
	- sphinxcontrib_jsmath - 3.9/3.10
	- sphinxcontrib_qthelp - 3.9/3.10
	- sphinxcontrib_serializinghtml - 3.9/3.10
[x] yarl - 3.10

----
so, plan is:

- remove old cython recipe
- pyzmq, cleanup, drop 3.9
- pyenet, cleanup, drop 3.9 (unkwon_horizons can wait, it is already broken).
- numpy, cleanup, drop 3.9
- pandas, move to 3.10
- sphinx / sphinx_* / sphinxcontrib_*, drop 3.9
- cython, drop 3.9