Remove frequency conversion in resonator frequency

[Edoardo-Pedicillo]

Checklist:

• Reviewers confirm new code works as expected.
• Tests are passing.
• Coverage does not decrease.
• Documentation is updated.
• Compatibility with Qibo modules (Please edit this section if the current pull request is not compatible with the following branches).
  • Qibo: master
  • Qibolab: main
  • Qibolab_platforms_qrc: main

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.32%. Comparing base (fa7e816) to head (e488b92).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #855   +/-   ##
=======================================
  Coverage   97.32%   97.32%           
=======================================
  Files         115      115           
  Lines        8645     8645           
=======================================
  Hits         8414     8414           
  Misses        231      231           

Flag	Coverage Δ
unittests	97.32% <100.00%> (ø)

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Files	Coverage Δ
...tocols/readout_optimization/resonator_frequency.py	99.00% <100.00%> (ø)