Removes legacy rapids-cmake cython implementations as it is deprecated in 24.08

[robertmaynard]

Description

rapids-cmake cython module has been deprecated since 24.02 and now can be removed in 24.08

This removes the cython module and instead only offers cython-core.

Checklist

• [x] I am familiar with the Contributing Guidelines.
• [x] New or existing tests cover these changes.
• [x] The documentation is up to date with these changes.
• [x] The cmake-format.json is up to date with these changes.

[robertmaynard]

@vyasr It would be good to get your opinion on this PR.

I was worried that dropping the rapids-cython.cmake would break people that included it but never used functions, so now it brings in the cython-core implementations.

[vyasr]

I don't think that's a major concern. In theory I suppose it could happen from copy-pasting top-level CMakeLists.txt files, which is I imagine how many projects that aren't RAPIDS projects I originally set up ended up with this code, but I'm not too worried about it.

OTOH I could see an argument for doing what you've done so that in the long run we could go back to rapids-cython rather than rapids-cython-core as the canonical module name. The -core suffix was primarily useful to differentiate, but once there's only one we could switch back.

[robertmaynard]

OTOH I could see an argument for doing what you've done so that in the long run we could go back to rapids-cython rather than rapids-cython-core as the canonical module name. The -core suffix was primarily useful to differentiate, but once there's only one we could switch back.

I like this option as well so lets go forward wit the PR as is.

[robertmaynard]

/merge