There is an updated pull request by ahesford against master on the void-packages repository

https://github.com/ahesford/void-packages python3-Cython-3.0.0
https://github.com/void-linux/void-packages/pull/45086

python3-Cython: update to 3.0.1.
This is a big update that reflects several years of extensive work, and needs some testing to be sure it doesn't break any Void packages.

#### Testing the changes
- I tested the changes in this PR: **in progress**

The following packages need to be fixed to build with new Cython:
- [ ] gbinder-python
- [ ] jack_mixer
- [ ] libimobiledevice
- [ ] memray
- [ ] pyliblo
- [x] python3-cypari2
- [x] python3-cysignals
- [ ] python3-efl
- [x] python3-fpylll
- [ ] python3-grpcio
- [ ] python3-h5py
- [ ] python3-jq
- [ ] python3-logbook
- [x] python3-lxml
- [ ] python3-mpi4py
- [ ] python3-pandas-msgpack
- [ ] python3-peewee
- [x] python3-pplpy
- [ ] python3-pyFFTW
- [ ] python3-pygame
- [x] python3-scikit-learn
- [x] python3-scipy
- [ ] python3-shapely
- [ ] python3-tables
- [ ] python3-uvloop
- [x] python3-yaml
- [ ] sagemath
- [ ] urh
- [ ] vapoursynth
- [ ] vidcutter

A patch file from https://github.com/void-linux/void-packages/pull/45086.patch is attached