Fix CMA callback

[andrea-pasquale]

CMA callback fixed by calling it for each evaluation and not for each iteartion.
Should fix tests randomly failing, see #1344 for example.

Checklist:

• Reviewers confirm new code works as expected.
• Tests are passing.
• Coverage does not decrease.
• Documentation is updated.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.82%. Comparing base (cb87952) to head (0858afd).

Additional details and impacted files

@@               Coverage Diff               @@
##           sparse_unitary    #1346   +/-   ##
===============================================
  Coverage           99.82%   99.82%           
===============================================
  Files                  72       72           
  Lines               10563    10572    +9     
===============================================
+ Hits                10544    10553    +9     
  Misses                 19       19           

Flag	Coverage Δ
unittests	99.82% <100.00%> (+<0.01%)	⬆️

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[MatteoRobbiati]

Thanks a lot @andrea-pasquale.