feat: build wheels

[beckermr]

This PR adds wheel builds.

to do:

• add code to install each wheel and run the test suite

[ntessore]

FWIW, I've found it very useful to have a manual trigger for the cibuildwheel workflow, with optional input for the git ref to be built, and optional cibw build/skip override. That way, you can always use the latest build workflow to backfill wheels of old releases, e.g., for new Python versions.

[beckermr]

OK @esheldon shall we merge?

[beckermr]

I can attempt to push the wheels using the workflow dispatch once the PR is merged.

[esheldon]

How are you testing that the wheels work, are available through pypi etc?

[beckermr]

So available on pypi we cannot test. If the uploads fail when it tries, we'll see the failure in CI and so I am not worried about that.

For testing the actual wheels, I am testing a single version of python (3.11 or 3.12 depending on the architecture). I use pytest directly running on the installed wheel.

See the sections of the workflow that look like this:

- name: test wheel for python ${{ env.PYVER }}
  run: |
    pystr='${{ env.PYVER }}'
    pystr=${pystr//./}
    python -m pip install pip
    pip install numpy pytest
    pip install ./wheelhouse/*cp${pystr}*.whl
    pytest --pyargs fitsio

[beckermr]

Shall we merge here?