Update macos version in github actions

[jepler]

Move from 11 (deprecated) to 12 (the oldest non-deprecated)

Because the artifacts formerly had the macos version number in the
mpy-cross binary filename, we have to change the binary name anyway.
Rename it without the macos version (e.g., mpy-cross-macos-x64 instead of
mpy-cross-macos-11-x64)

https://github.blog/changelog/2024-05-20-actions-upcoming-changes-to-github-hosted-macos-runners/

Closes: #9328

[jepler]

This also adds a new dependency on setuptools, needed for the silabs port when using python 3.12 and newer, which removed distutils

[bill88t]

Removing the version name from the file itself but not the folder isn't ideal.
I know there is a macos folder already, but can't that be renamed to something else so that macos is used for this?

[jepler]

@bill88t thanks, fixed

[bill88t]

Looks good!

[dhalbert]

Thank you for working this out. I won't merge in case we want to stage this with other PR's that will adjust the names and paths accordingly.

[jepler]

I don't think there's anything we need to take care to do at the same moment. Until changed, for example, circuitpython_build_tools will always use mpy-cross from 9.0.0-alpha.2 (!) for creating its 9.x mpy files.

If we can drop 8.x from circuitpython_build_tools at the same time as we add 9.1 or 10, we can change it then to simply use the new path. If we need to keep 8.x support we'll need to add some version dependent checking for the mpy cross location. but I think this can all be handled in its own time and based on the issue I filed in circuitpython_build_tools.