iOS builds

[Edward-Knight]

Now PEP 730 is in Python 3.13, it would be good to revive the iOS builds on this project. These were removed in 0ce1527 due to CI overhead and lack of testing/use:

These aren't released and haven't been tested thoroughly. macOS GitHub
Actions runners slow down the CI for this project and this annoys me.
The addition of 3.11 builds is going to make the situation worse. So
let's just disable the iOS builds from CI to keep CI responsive.

I'm hoping now that iOS is officially supported at tier 3, maintaining iOS builds will be less burdensome going forward.

At the moment we're using https://github.com/beeware/Python-Apple-support instead (and compiling ourselves), but haven't tried out 3.13 yet.

https://docs.python.org/3/using/ios.html#using-ios

[zanieb]

Unfortunately macOS is still a major bottleneck in CI — but otherwise I'm supportive of this.