[Cython] Progress towards Cython 3.0

[Stefan Behnel]

Hi,

tl;dr: help with the remaining work would be appreciated.

The "3.0" milestone on github currently lists 24 open tickets, so there's
still quite a bit to do before the release. Some of them are already PRs
that need more work in one way or another.

https://github.com/cython/cython/milestone/58

The upside is that we've already closed twice as many issues as are still open.

https://github.com/cython/cython/issues?utf8=✓&q=is%3Aclosed+type%3Aissue+milestone%3A3.0

I went through the open issues and marked everything as "blocker" that
represents behavioural changes. We should make sure to include those in
this release, or postpone them to the next major release.

https://github.com/cython/cython/issues?utf8=%E2%9C%93&q=is%3Aopen+label%3A%22P%3A+blocker%22+milestone%3A3.0

Some tickets seem easy to do (marked as "good first issue"). But also the
"binding" PR is a big one that will need some more fiddling with the
details, some of which can be investigated separately.

https://github.com/cython/cython/pull/2864

Any help with the open issues would be greatly appreciated.

Stefan