Add macos runners

• I moved the pre-commit job to a different stage. I think it's more natural as all other jobs wait for it. But it might be subjective :-) I can remove that commit if you think otherwise.
• Add job to run build with catch2 on macOS (both x86_64 and Apple Silicon). All needed dependencies are installed with micromamba. I do believe this is the easiest and most straightforward way. I tested homebrew a while ago and it was very slow on gitlab saas runners. Plus it doesn't include tango-idl that would need to be compiled. But if you have a better solution, feel free :-)

Fix #1267

Jobs:

• macos:osx-arm64: 3mn26
• macos:osx-64: 9mn49 (using rosetta on Apple Silicon)