Add error message for shot vectors for QiskitDevice

[austingmhuang]

As mentioned by @CatalinaAlbornoz in issue #575, there's a bug that's ultimately related to qiskit.aer not supporting shot vectors (@albi3ro). While the functionality is still not supported, in this PR, we add a more useful error message to capture this behaviour.

This error message already exists in the new device API so there's no additional work on that front.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (a295ece) to head (aa7aa42).

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            9         9           
  Lines          867       869    +2     
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+ Hits           867       869    +2     

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[soranjh]

You can use @pytest.mark.parametrize.

[albi3ro]

You may also need to update the setter for shots.

If you do:

dev.shots = (10,100,100)

Do you get an error? This is what is used for dynamic shots.

We should double check that bug #575 actually provides an informative error message now.

[austingmhuang]

You may also need to update the setter for shots.

If you do:

dev.shots = (10,100,100)

Do you get an error? This is what is used for dynamic shots.

We should double check that bug #575 actually provides an informative error message now.

dev.shots = (10, 100, 100)

Does not raise an error for qiskit.aer since it does not have a setter for shots (inherits from the legacy device).
Seems like the error message doesn't show up for #575 when using qiskit.aer.

---

I tried using qiskit.remote with AerSimulator instead. This does raise an error for dev.shots=(10, 100, 100) but for the example in #575 the error message does not show up. Not sure how to proceed.

[albi3ro]

You may also need to update the setter for shots.
If you do:

dev.shots = (10,100,100)

Do you get an error? This is what is used for dynamic shots.
We should double check that bug #575 actually provides an informative error message now.

dev.shots = (10, 100, 100)

Does not raise an error for qiskit.aer since it does not have a setter for shots (inherits from the legacy device). Seems like the error message doesn't show up for #575 when using qiskit.aer.

I tried using qiskit.remote with AerSimulator instead. This does raise an error for dev.shots=(10, 100, 100) but for the example in #575 the error message does not show up. Not sure how to proceed.

We may need to define a shots setter to add some validation is a shot vector is attempted to be set.