Fix wheels for macOS

[hugovk]

Description

The macos-14 wheel build has started failing:

Running on architecture: arm64
Error: Expected x86_64 but got arm64

https://github.com/tskit-dev/tskit/actions/runs/21176931185/job/60908346904

This is because macos-14 is now ARM-only.

macos-15 is still ARM-only, but there's a new macos-15-intel:

• https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/

Also:

• Bump GitHub Actions
• Add colour to GitHub Actions logs for readability
• Fix deprecation warning in GHA

PR Checklist:

• [n/a] Tests that fully cover new/changed functionality.
• [n/a] Documentation including tutorial content if appropriate.
• [n/a] Changelogs, if there are API changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.76%. Comparing base (6b9fb79) to head (4e29cd3).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3371   +/-   ##
=======================================
  Coverage   89.76%   89.76%           
=======================================
  Files          29       29           
  Lines       31292    31292           
  Branches     5738     5738           
=======================================
  Hits        28089    28089           
  Misses       1794     1794           
  Partials     1409     1409           

Flag	Coverage Δ
c-tests	86.77% <ø> (ø)
lwt-tests	80.38% <ø> (ø)
python-c-tests	87.12% <ø> (ø)
python-tests	98.85% <ø> (ø)
python-tests-no-jit	33.51% <ø> (ø)
python-tests-numpy1	50.28% <ø> (ø)

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[jeromekelleher]

Thanks @hugovk - can you review this please @benjeffery?

[jeromekelleher]

I'm going to go ahead and merge this as it all looks like it's working. Thanks again @hugovk!