Prepare Python wheel releases

[tnull]

Build Python-ABI-independent wheels for supported Linux and macOS targets so users can install LDK Node directly from PyPI.

Keep build and publication available through local scripts. Require the complete artifact set on TestPyPI before production, and exercise the bindings on the oldest and newest supported CPython versions.

[ldk-reviews-bot]

👋 Thanks for assigning @tankyleo as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[valentinewallace]

This is pretty outside of my wheelhouse (ba dum tiss), and I was planning to sink a lot of my review bandwidth into https://git.rust-bitcoin.org/lightningdevkit/rust-lightning/pulls/4872 in the coming days, so FYI my first impression is that it may take me a little while to get to this and then take a while to get up to speed on it.

[tnull]

This is pretty outside of my wheelhouse (ba dum tiss), and I was planning to sink a lot of my review bandwidth into https://git.rust-bitcoin.org/lightningdevkit/rust-lightning/pulls/4872 in the coming days, so FYI my first impression is that it may take me a little while to get to this and then take a while to get up to speed on it.

Okay. Now reassigned @tankyleo as we'll need this for next week's release (worst case I just run the updated scripts locally without prior review).

Rebased after #1040 landed.

[tnull]

Now also amended to allow building macOS x86_64 wheels on aarch64 macs.