Add 32bit platform wheels

[mtreinish]

It would be great if there were wheels published to PyPI for 32bit platforms for projects that support 32bit platforms. This is primarily a request to just to add builds for i686 manylinux and win32 wheels.

I took a look at doing this but got a bit lost in all the conda specific tooling to do the build and wasn't sure how to setup the machinery to setup a 32 bit conda env. For other projects where I've done this I've used https://github.com/joerick/cibuildwheel/ to build the wheels which automates the builds in CI.

[isuruf]

conda-forge which we are using for builds here, don't support i686 builds anymore. Reason for using conda based builds were because of all the dependencies like LLVM, GMP, MPFR, FLINT that we have to compile. All of these support i686, but they are hard to build. We had scripts to build them and it was becoming harder and harder to maintain them and finally made the switch to conda to manage the dependencies.

[mtreinish]

Well at least for linux a good chunk of those can be installed from distro packages. For example, if you used the manylinux i686 docker image which is centos based all of those are in the centos package repository (llvm is preinstalled in the manylinux docker image), except for flint I think (which doesn't look like it's terrible to build on linux).

The windows story is more complicated though, there are package managers but they tend to be hit or miss (llvm and gmp probably are easier but the others I doubt we'd find prebuilt binaries). So yeah I guess for win32 wheels the only way to do this would be to support scripts to build every compiled dependency from source which I definitely can see being harder to maintain longer term.