Use macos-15-intel GA runner

[ericpre]

Progress of the PR

• Use macos-15-intel GA runner,
• fix and clean-up CI setup for testing on python3.13t,
• bump cibuildwheel to v3.2.1 and cleanup release workflow,
• [n/a] update docstring (if appropriate),
• [n/a] update user guide (if appropriate),
• [n/a] add a changelog entry in the upcoming_changes folder (see upcoming_changes/README.rst),
• [n/a] Check formatting of the changelog entry (and eventual user guide changes) in the docs/readthedocs.org:rosettasciio build of this PR (link in github checks)
• [n/a] add tests,
• ready for review.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.12%. Comparing base (7d6820e) to head (559ebcc).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #452   +/-   ##
=======================================
  Coverage   88.12%   88.12%           
=======================================
  Files          91       91           
  Lines       11811    11811           
  Branches     2191     2191           
=======================================
  Hits        10409    10409           
  Misses        884      884           
  Partials      518      518           

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