CompatHelper: bump compat for QuantumToolbox to 0.15, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the QuantumToolbox package from 0.13 - 0.14 to 0.13 - 0.14, 0.15.
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 92.11%. Comparing base (0b7924d) to head (fe055d6).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #106      +/-   ##
==========================================
+ Coverage   89.08%   92.11%   +3.03%     
==========================================
  Files          20       20              
  Lines        1484     1484              
==========================================
+ Hits         1322     1367      +45     
+ Misses        162      117      -45     

Flag	Coverage Δ
	54.47% <ø> (?)

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