Changes unknown
when pulling 3db0f4e on eriknw:no_numba
into ** on python-graphblas:main**.

PyPy 3.8.16 0_73_pypy had a segfault here when using psg wheel, so I'm skipping PyPy on CI for now (not worth the effort). Most of the PyPy jobs were passing though!

I'm not sure when I'll be able to push this PR over the finish line, but it's reviewable in its current state. Most of the changes are pretty minor, and it was mostly just grunt-work to get tests to pass w/o numba installed.

This PR does not yet introduce "udf" backends or a means to make numba optional when installing.

Using numba==0.57.0rc1 appears to work! 🎉 (also NumPy 1.24 and Python 3.11)

I think this is ready for review/closer scrutiny.

This sets us on the path of having numba and even suitesparse-graphblas as optional dependencies. Documentation has been updated to show pip install python-graphblas[default].

We may want to wait until numba 0.57 is released to merge this.

I futz around with coverage a little bit, and in the process fixed a few bugs. I also commented code e.g. # NOT COVERED, # BRANCH NOT COVERED, and # FLAKY COVERAGE to call attention.

Anyway, this is going in! I skip numba 0.57.0rc1 on Windows in CI. We can update CI when there is a new RC, and/or when 0.57.0 is released.

One final reminder: I am curious whether it's better to use isclose as a UDF or a recipe. We have both. We should experiment.