[Build] Add mac build for Mac OS 14 and 15

[hughperkins]

Issue: #

Brief Summary

Add mac build for Mac OS 14 and 15

Note that this will fail without a ton of additional changes.

• open question whether we want to merge this in (with it failing), and then merge in additional things, bit by bit, until the mac build passes?
• or create one 'big bang' pr
• I feel that the first approach will be much easier, and cleaner?

copilot:summary

Walkthrough

copilot:walkthrough

[hughperkins]

Let's wait till linux runner is merged in before continuing with this one. Since we need some of the changes from linux runner. I'll set this to 'draft' for now.

[hughperkins]

Note: @duburcqa see discussion here, https://genesis-ai-company.slack.com/archives/C08UKDR6KGR/p1749076147261559 Your thoughts?

[hughperkins]

This might build now 🤔

[hughperkins]

Interesting: these are genuine failures:

FAILED tests/python/test_matrix.py::test_cross_scope_matrix_atomic_ops[arch=arm64-0]
FAILED tests/python/test_matrix.py::test_cross_scope_matrix_atomic_ops[arch=metal-1]
= 2 failed, 3414 passed, 317 skipped, 996 warnings, 6 rerun in 646.21s (0:10:46) =

[hughperkins]

Hi @duburcqa I've added skipif to one of the tests, for Mac.

• it passes when run single-threaded
• I tried using xfail, but it seg faults, so xfail just becomes an actual failure, unforutnately
• I've created a ticket in Linear at https://linear.app/genesis-ai-company/issue/CMP-31/fix-failing-test-cross-scope-matrix-atomic-ops-on-mac-in-multiprocess , to track this
• Please could you confirm you are still ok-ish for this to be merged?

[duburcqa]

This is concerning but OK. Better be in a clean state and repair stuffs after.