Troubleshoot and Fix the Mac Build

[s2t2]

We see that the build is passing on Linux, but failing on Mac.

It could be that things are just timing out, and things are taking too long to install via homebrew. We noticed the Mac build was taking a very long time. But it could be a different issue.

We need to troubleshoot the issue, and ideally fix it to keep Mac support. Otherwise we should remove Mac support from the build (not ideal, only if necessary).

Someone who is comfortable with GitHub Actions would be great person to tackle this issue!

[AvishKaushik]

Hi @s2t2 ,

I've identified and fixed the issue in PR #133 .

Root cause: The macos-13 runner has been deprecated by GitHub Actions, causing the build failures.
Fix: Updated to macos-15-intel runner (official replacement, supported until August 2027).
Result: All builds now passing (Ubuntu, macOS ARM, macOS Intel).

Test run: https://github.com/AvishKaushik/sbsim/actions/runs/20201182727

The issue could have been in Homebrew timeouts for macOS-13 (intel-based) but we won't be able to test macOS-13 image as it is retired (actions/runner-images#13046)