ci.yml: Upgrade some jobs to run on macos-latest

[cclauss]

Failures discussed at

• Test upgrade to macos-12. #392 (comment)

Suppress with:
--> @pytest.mark.xfail(macos_version() > (12, ), reason="setup.py xxx is deprecated")

• https://packaging.python.org/en/latest/discussions/setup-py-deprecated

[fangerer]

Thanks for the effort but I think this should not be merged as it is.
Using macos-latest is, ofc, fine and we should do that.
However, the current solution just passes tests because of the xfail annotations. This means, we are no longer running the marked tests because they all fail on macos-12 and if they break on macos-11, we won't notice.

Until I find the time to investigate and properly fix that, I would be fine if we add a CI job that runs just those tests on macos-11.

[cclauss]

All of this is a bit strange on GitHub Actions because the current macOS is v14.2 but given that GHA runs on Intel Macs, the highest version we can test on is 12.

UPDATE: macOS 14 on M1 is now available on GitHub Actions.

[cclauss]

Did Add main_tests os: macos-11 on python-version: 3.12 do what you were requesting or did I misunderstand?

[cclauss]

Over the next 12 weeks, jobs using the macos-latest runner label will migrate from macOS 12 (Monterey) to macOS 14 (Sonoma).

https://github.blog/changelog/2024-04-01-macos-14-sonoma-is-generally-available-and-the-latest-macos-runner-image