Add standard CI cases using Python 3.13

[speth]

Changes proposed in this pull request

• Add standard CI runs using Python 3.13
• Update macOS runner version to include the most recent one (macos-15) and drop macos-12 which is pending removal by GitHub

The one test failure is caused by the example that uses CoolProp, which has not yet been updated for Python 3.13.

Checklist

• The pull request includes a clear description of this code change
• Commit messages have short titles and reference relevant issues
• Build passes (scons build & scons test) and unit tests address code coverage
• Style & formatting of contributed code follows contributing guidelines
• The pull request is ready for review

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.26%. Comparing base (e36c9b9) to head (2dfeada).
Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1808   +/-   ##
=======================================
  Coverage   73.26%   73.26%           
=======================================
  Files         383      383           
  Lines       54620    54620           
  Branches     9099     9099           
=======================================
  Hits        40016    40016           
  Misses      11601    11601           
  Partials     3003     3003           

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[bryanwweber]

Fortunately, pint 0.24.4 was just released that resolves hgrecco/pint#1969, so Python 3.13 tests won't fail for that reason!

[ischoegl]

Thanks! This all looks good to me! (The one failing example appears to be an upstream issue in CoolProp)