CompatHelper: bump compat for Trixi to 0.16, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Trixi package from 0.15 to 0.15, 0.16.
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 97.09%. Comparing base (097086e) to head (9a64827).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #170   +/-   ##
=======================================
  Coverage   97.09%   97.09%           
=======================================
  Files          37       37           
  Lines        5019     5019           
=======================================
  Hits         4873     4873           
  Misses        146      146           

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[ranocha]

Should be done in #169