Make PrimitiveJob serializable

[kt474]

Summary

In qiskit-ibm-runtime we want to add job methods to our QiskitRuntimeLocalService (Issue Qiskit/qiskit-ibm-runtime#1607). In order to save PrimitiveJob objects locally we need a way to serialize them. It's currently not serializable due to the use of ThreadPoolExecutor:

qiskit/qiskit/primitives/primitive_job.py

Lines 47 to 48 in 35d0954

	executor = ThreadPoolExecutor(max_workers=1) # pylint: disable=consider-using-with
	self._future = executor.submit(self._function, *self._args, **self._kwargs)

Credit to @t-imamichi

Details and comments

Also fixes #12787

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core
• @ajavadia
• @levbishop
• @t-imamichi

[coveralls]

Pull Request Test Coverage Report for Build 12378436884

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 14 of 20 (70.0%) changed or added relevant lines in 1 file are covered.
• 59 unchanged lines in 6 files lost coverage.
• Overall coverage increased (+0.02%) to 88.951%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/primitives/primitive_job.py	14	20	70.0%

Files with Coverage Reduction	New Missed Lines	%
qiskit/circuit/library/quantum_volume.py	1	93.18%
qiskit/circuit/library/arithmetic/adders/adder.py	2	91.49%
crates/qasm2/src/lex.rs	4	91.98%
crates/qasm2/src/parse.rs	6	97.62%
crates/circuit/src/circuit_data.rs	7	95.43%
qiskit/transpiler/passes/synthesis/hls_plugins.py	39	87.02%

Totals
Change from base Build 12275601740:	0.02%
Covered Lines:	79430
Relevant Lines:	89296

---

💛 - Coveralls

[t-imamichi]

It looks good overall. Could you add a reno to describe that both DataBin and PrimitiveJob become serializable?

[t-imamichi]

LGTM. Could you ask someone else to review it too just in case?

[t-imamichi]

I recall that this method is used when we serialize a job. But, this method is not used any other methods of this class. So, it might be good to add a comment just in case though it is a private method.

[kt474]

Added in fac959a