Delete boost::math::is_trivial & is_trivial_v.

[Romain-Geissler-1A]

std::is_trivial is deprecated in C++ >+ 26, and these aren't used anywhere in the internal Boost.Math code.

[mborland]

Thanks! I approved the CI run, and will merge once it has cycled

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.24%. Comparing base (0eacea6) to head (868f959).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1324   +/-   ##
========================================
  Coverage    95.24%   95.24%           
========================================
  Files          814      814           
  Lines        69309    69309           
========================================
  Hits         66015    66015           
  Misses        3294     3294           

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