Re-consider requiring the full qiskit package instead of its sub-elements

[andreamari]

Some motivations for requiring the full qiskit package instead of individual elements are:

• We require pennylane-qiskit, which requires qiskit.
• By requiring qiskit we would avoid pip/dependabot installation conflicts of individual elements. E.g. Update qiskit-ibmq-provider requirement from ~=0.16.0 to ~=0.17.0 #980. See also this comment by @rmlarose (Fix pip package resolving problems #976 (comment)).
• The main drawback is the installation of qiskit-acqua that we don't need. However, qiskit-acqua is deprecated and, in the near future, will be separated from qiskit (see first note here: https://github.com/Qiskit/qiskit-aqua).

[nathanshammah]

To me it sounds fine given your comments.

[trbromley]

We have a similar issue (PennyLaneAI/pennylane-qiskit#149) in the PennyLane-Qiskit plugin, but there suggesting the alternative approach of relying on the sub-packages rather than full qiskit.

[andreamari]

This idea is having a Rabi oscillation between Mitiq and PL 😄

[github-actions]

This issue had no activity for 2 months, and will be closed in one week unless there is new activity. Cheers!

[andreamari]

This was closed by #993