Update Python support to 3.10-3.14, drop EOL versions

[AaronDJohnson]

• Drop EOL Python versions 3.8 and 3.9
• Add support for Python 3.13 and 3.14
• Fix macOS runner for Python 3.10 by swapping to Intel based runner (none exist for ARM)
• Fix SuiteSparse paths for ARM macOS by dynamically resolving with brew --prefix
• Bump actions/checkout and actions/setup-python versions

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.50%. Comparing base (a71cb14) to head (b56a817).
⚠️ Report is 24 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev     #437   +/-   ##
=======================================
  Coverage   72.50%   72.50%           
=======================================
  Files          13       13           
  Lines        3466     3466           
=======================================
  Hits         2513     2513           
  Misses        953      953           

Files with missing lines	Coverage Δ
enterprise/pulsar.py	28.76% <100.00%> (ø)
enterprise/signals/anis_coefficients.py	12.14% <ø> (ø)
enterprise/signals/gp_priors.py	85.33% <100.00%> (ø)
enterprise/signals/selections.py	58.47% <ø> (ø)
enterprise/signals/signal_base.py	90.91% <ø> (ø)
enterprise/signals/utils.py	82.18% <100.00%> (ø)
enterprise/signals/white_signals.py	98.61% <ø> (ø)

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