hotfix Cython<3, else can't install

[skjerns]

With newest Cython version 3.0, something with finding the modules is broken. Until we have time to dive for a solution, I propose this hotfix to set Cython<3. As the Build is done in its own env, this should have no impact on the base env that we are installing to, ie. no side-effects

See #233

[OlivierKessler01]

Please @skjerns merge this asap, using --no-build-isolation and installing cython in userland, while working on simple and well isolated projects, doesn't make for a proper fix since the cython version would conflict with other compiling needs.

[skjerns]

However, install should still be possible using the wheels on pypi, or do you require the dev version?

(I'm not sure if there is a way to install using pypi and having to use Cython?)

[OlivierKessler01]

However, install should still be possible using the wheels on pypi, or do you require the dev version?

(I'm not sure if there is a way to install using pypi and having to use Cython?)

We are running 0.1.20 on musl based platforms, so no wheels available at the time, had I checked I would've seen that more recent versions of pyedflib provided wheels for us.

Cheers ! :)