CompatHelper: bump compat for NFFT to 0.14, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the NFFT package from 0.13 to 0.13, 0.14.
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 100.00%. Comparing base (3e70ee7) to head (8dc42c3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #142      +/-   ##
===========================================
+ Coverage   99.92%   100.00%   +0.07%     
===========================================
  Files          38        38              
  Lines        1365      1364       -1     
===========================================
  Hits         1364      1364              
+ Misses          1         0       -1     

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