Use `macos-14` as MacOS runners in CI

[ericcornelissen]

Relates to #18

Summary

Update all continuous integration jobs that run on MacOS to use macos-14 instead of macos-13. This was released yesterday and is still in beta, hence this is just for trying it out and seeing if it works. EDIT: As of 2024-04-01 this is generally available.

See also

• https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source/
• https://github.blog/changelog/2024-01-30-github-actions-macos-14-sonoma-is-now-available/

[ericcornelissen]

As of 2024-04-01 this should be good to go, see: https://github.blog/changelog/2024-04-01-macos-14-sonoma-is-generally-available-and-the-latest-macos-runner-image/.