Rabi and chevron fixes

[andrea-pasquale]

Closes #957 and #956 (comment)
For Rabis I just made the bounds a bit larger and change some initial conditions.
For Chevron I did a small refactor of the fit in order to take no longer the FFT but the row where there are more oscillations.

I've tested both and they seems to work as expected.

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 97.49%. Comparing base (6961ed1) to head (f8e36a0).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #961      +/-   ##
==========================================
- Coverage   97.58%   97.49%   -0.09%     
==========================================
  Files         118      118              
  Lines        9057     9057              
==========================================
- Hits         8838     8830       -8     
- Misses        219      227       +8     

Flag	Coverage Δ
unittests	97.49% <100.00%> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/qibocal/protocols/coherence/spin_echo.py	100.00% <100.00%> (ø)
src/qibocal/protocols/rabi/amplitude.py	96.87% <100.00%> (ø)
src/qibocal/protocols/rabi/amplitude_signal.py	97.46% <100.00%> (ø)
src/qibocal/protocols/rabi/utils.py	100.00% <ø> (ø)
...protocols/two_qubit_interaction/chevron/chevron.py	96.96% <ø> (-2.28%)	⬇️
...c/qibocal/protocols/two_qubit_interaction/utils.py	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes

[Jacfomg]

👍

[alecandido]

I checked the code and seems fine. I didn't test on hardware myself, but I saw you did, so I just trust the results in the OP