Enable support for cython 3

[chrhansk]

This is an attempt to fix #211:

• All callbacks are now marked noexpect with exceptions being handled (stored) internally
• A large try / expect block is used in the callbacks, where code outside of the blocks should not throw (only stack allocations)
• The large Jacobian / Hessian callbacks have been split up into value / structure callbacks
• Cython restriction to <3 was removed

[chrhansk]

Edit: Everything is cast to Problem rather than object in this patch, so the callbacks have access to all (not just public) cdef properties, which could now be made private (by removing the public) without problems.

[moorepants]

This will need to run with Cython 0.29.* and 3+. Does it?

[chrhansk]

It is supposed to and does on my system.

[musicinmybrain]

This will need to run with Cython 0.29.* and 3+. Does it?

This works for me (builds and tests pass, except any pre-existing issues like https://github.com/mechmotum/cyipopt/issues/237 and https://github.com/mechmotum/cyipopt/issues/238) on Fedora Linux Rawhide as well. (I did also test it with Cython 0.29.35 for completeness.) I’ll probably go ahead and apply this as a downstream patch in Rawhide, since this is one of a handful of packages that still needs Cython 0.29, and we’d like to stop maintaining that compat package sooner rather than later.

[moorepants]

I've gone through this and I don't see any issues with the changes. Thanks.

[chrhansk]

Thank you for the merge.