Make drive non user-facing

[Qottmann]

Making drive non user-facing.
Pro:

• functionality already provided by rydberg_drive or transmon_drive(amp, phase, 0, wires)
• less maintenance

Con:

• one off extra work: for code quality it would make sense to remove the function alltogether and just have rydberg_drive
• lose the nice "theoretical background page that relates the Hamiltonians for different conventions / fields (though could still keep/move those in rydberg_drive and transmon_drive

Background:
Originally thought we could unify all drives because they are doing the same. While this is indeed the case, it makes sense to have different functions for different physical systems because conventions are different. I.e. for Rydberg atoms where all qubits have the same energy gap, it makes more sense to talk about detuning from that uniform energy gap (/frequency). For transmons that is not the case, and different qubits have different resonance frequencies. Hence the drive frequency is used explicitly.

[github-actions]

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[codecov]

Codecov Report

Merging #4021 (5e39d27) into master (a87fca3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4021   +/-   ##
=======================================
  Coverage   99.58%   99.58%           
=======================================
  Files         351      351           
  Lines       30850    30850           
=======================================
  Hits        30721    30721           
  Misses        129      129           

Impacted Files	Coverage Δ
pennylane/pulse/__init__.py	100.00% <ø> (ø)
pennylane/pulse/transmon.py	100.00% <ø> (ø)

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[lillian542]

Looks good!

[mudit2812]

Thanks Korbinian!