Deprecate Qobj input to UnitarySimulatorPy.run

[rupeshknn]

Summary

qiskit.providers.basicaer.UnitarySimulatorPy.run() never deprecated a qiskit.qobj.QasmQobj input and will still support it while the qasm simulator and statevector simulator will not. This PR to stable/0.46 deprecates this functionality, and #11395 to main removes it.

Fixes #11046

Based on the conversation here with @1ucian0 I'll start with a deprecation PR to stable/0.46 and once that's done, I'll do a removal PR to main.

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[rupeshknn]

@1ucian0 This PR has been ready for review. can you review this?

[ElePT]

LGTM, this is a very well done deprecation, thanks a lot for the attention to detail. My only comment is that we don't generally document API docs changes in our changelog, so there is no need for the fixes section of the reno.