CompatHelper: bump compat for Trixi to 0.16 for package LibTrixi.jl, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Trixi package from 0.15 to 0.15, 0.16 for package LibTrixi.jl.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.11%. Comparing base (6339f3e) to head (425750d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #282   +/-   ##
=======================================
  Coverage   96.11%   96.11%           
=======================================
  Files          25       25           
  Lines        1260     1260           
  Branches       74       74           
=======================================
  Hits         1211     1211           
  Misses         45       45           
  Partials        4        4           

Flag	Coverage Δ
unittests	96.11% <ø> (ø)

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