Migrate from the custom M1 runner to the official Github one

[Gedochao]

Version(s)
v1.3.2

Describe what needs to be done and why
We are currently using our own custom MacOS M1 runner for aarch64 jobs. We could and should migrate to the official M1 runner provided by GitHub. This would also enable us to run those jobs outside of the main branch, even on external contributor PRs.

Requirements

• migrate scala-cli jobs to macos-14
• implement a script verifying the architecture for MacOS builds (as there is no separate MacOS runner nametag for the new architecture, just a version descriptor)
• migrate coursier-m1 jobs to macos-14
• migrate https://github.com/VirtusLab/scala-cli-setup jobs to macos-14

Describe alternatives you've considered
We could stay on the custom runner we are using, but this should make it easier to maintain long-term (as someone would be doing a big chunk of the maintenance for us from then on)

Additional context

• GitHub Action: New M1 runner available to all plans, including open source 🚀 actions/runner-images#9254
• https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source/

[mkurz]

Maybe relevant?

• https://github.blog/2024-06-03-arm64-on-github-actions-powering-faster-more-efficient-build-systems/