Remove qobj, deprecated in 1.2

[1ucian0]

In #12649, qobj and assemble was deprecated. Time to remove it.

• qiskit/qobj/common.py:26 (__init__)
• qiskit/qobj/pulse_qobj.py:32 (__init__)
• qiskit/qobj/pulse_qobj.py:101 (__init__)
• qiskit/qobj/pulse_qobj.py:302 (__init__)
• qiskit/qobj/pulse_qobj.py:411 (__init__)
• qiskit/qobj/pulse_qobj.py:509 (__init__)
• qiskit/qobj/pulse_qobj.py:536 (__init__)
• qiskit/qobj/pulse_qobj.py:594 (__init__)
• qiskit/qobj/qasm_qobj.py:27 (__init__)
• qiskit/qobj/qasm_qobj.py:212 (__init__)
• qiskit/qobj/qasm_qobj.py:296 (__init__)
• qiskit/qobj/qasm_qobj.py:438 (__init__)
• qiskit/qobj/qasm_qobj.py:482 (__init__)
• qiskit/qobj/qasm_qobj.py:530 (__init__)
• qiskit/qobj/qasm_qobj.py:593 (__init__)
• qiskit/qobj/converters/lo_config.py:27 (__init__)
• qiskit/qobj/converters/pulse_instruction.py:114 (__init__)
• qiskit/compiler/assembler.py:44 (assemble)

[eliarbel]

It would be good to refactor BasicSimulator a bit to not depend on _assemble anymore, which will facilitate a clean removal of qobj et al. I think it makes sense to include it also for 2.0, what do you think?

[ElePT]

Related PRs:

• BasicSimulator refactoring: Remove use of deprecated objects in BasicSimulator #13743
• Removal of qiskit/compiler/assembler.py: Remove assemble and assembler module #13748