Add deprecation warning on use of qiskit.IBMQ

[mtreinish]

Summary

With the pending release of the qiskit-ibm-provider that superscedes the
qiskit-ibmq-provider package. The qiskit-ibmq-provider is now deprecated
and will be retired/archived in the future. In coordination with that
this commit deprecates the lazy loading fixture qiskit.IBMQ and removes
documentation references to qiskit-ibmq-provider in the repo.

Details and comments

This is on hold until the qiskit-ibm-provider package has its first release

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[HuangJunye]

This part has an additional sentence "Just replace 'qiskit.IBMQ' with 'qiskit_ibm_provider.IBMProvider'" Is this intended?

[coveralls]

Pull Request Test Coverage Report for Build 3951291056

• 0 of 2 (0.0%) changed or added relevant lines in 1 file are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.03%) to 84.874%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qiskit/init.py	0	2	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/sabre_swap/layer.rs	2	98.95%
qiskit/pulse/library/waveform.py	3	91.67%

Totals
Change from base Build 3951289784:	0.03%
Covered Lines:	66095
Relevant Lines:	77874

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💛 - Coveralls

[HuangJunye]

Overall looks good to me. I did a quick search in the whole repo, and found a few places still need update the new import path. Can you please make those changes?

• https://github.com/Qiskit/qiskit-terra/blob/3241978340f534b76e4cf0e5e25ed16e2af5cf78/tools/update_fake_backends.py#L22
• https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/tools/jupyter/__init__.py#L28
• https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/tools/jupyter/__init__.py#L42
• https://github.com/Qiskit/qiskit-terra/blob/d3243e9e1d0e916e1d2c4af442011605204598b0/qiskit/providers/fake_provider/__init__.py#L73

I am not sure whether we should also update the path in this line in ibmq_mock.py,

• https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/test/ibmq_mock.py#L45

Do you need to add a test for deprecation and a release note as well?

[mtreinish]

Overall looks good to me. I did a quick search in the whole repo, and found a few places still need update the new import path. Can you please make those changes?

* https://github.com/Qiskit/qiskit-terra/blob/3241978340f534b76e4cf0e5e25ed16e2af5cf78/tools/update_fake_backends.py#L22

* https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/tools/jupyter/__init__.py#L28

* https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/tools/jupyter/__init__.py#L42

* https://github.com/Qiskit/qiskit-terra/blob/d3243e9e1d0e916e1d2c4af442011605204598b0/qiskit/providers/fake_provider/__init__.py#L73

Done in: e4ed253

I am not sure whether we should also update the path in this line in ibmq_mock.py,

I just dropped that module in: e4ed253 it was only there for legacy reasons in the docs. It's sole usage was for jupyter execute docs to be able to use qiskit.IBMQ and mock the calls to return a fake backend. Since we don't care about pretending that the ibm provider is part of the qiskit namespace anymore and we're no longer using jupyter execute this had no relevance so it was easier to just remove it as I don't think anything externally should have been using it.

* https://github.com/Qiskit/qiskit-terra/blob/95a97ec53caddc885d02fd353e8d0c745328fd39/qiskit/test/ibmq_mock.py#L45

Do you need to add a test for deprecation and a release note as well?

I added a release note in 7ec28f4 tests for this are a bit weird as they require the ibmq provider to be installed which we purposely don't install in tests. All we'd be testing is that a deprecation warning is emitted as we can't really test anything functional about the alias without having credentials and ibmq installed.

[mtreinish]

as I don't think anything externally should have been using it.

Sigh, I stand corrected the ibmq provider was using it for it's jupyter-execute docs which were copied over from terra when that split out (because of course why would it be simple): https://github.com/Qiskit/qiskit-ibmq-provider/search?q=mock_get_backend let me add the function back in for now. We can just drop it when we drop qiskit.IBMQ

[HuangJunye]

Just one small comment for the release note.

[HuangJunye]

LGTM!