Added warning filter to ignore warning

[bdg221]

Fixes #2103

Description

When running test_closest_positive_distribution_error() from test_inverse_confusion_matrix.py the following warning is given:

mitiq/rem/tests/test_inverse_confusion_matrix.py::test_closest_positive_distribution_error
  /home/runner/work/mitiq/mitiq/mitiq/rem/inverse_confusion_matrix.py:145: RuntimeWarning: invalid value encountered in divide
    init_guess /= np.sum(init_guess)

Since this is expected to raise an error with an invalid input, the warning is not necessary and should be disabled.

Steps to Duplicate

To duplicate this behavior locally, run make test then search the output for the warning.

License

• I license this contribution under the terms of the GNU GPL, version 3 and grant Unitary Fund the right to provide additional permissions as described in section 7 of the GNU GPL, version 3.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.28%. Comparing base (c5afbd4) to head (34dbd88).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2211      +/-   ##
==========================================
- Coverage   98.31%   98.28%   -0.03%     
==========================================
  Files          90       90              
  Lines        4262     4262              
==========================================
- Hits         4190     4189       -1     
- Misses         72       73       +1     

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[natestemen]

Awesome, thanks Brian! Are there any other tests that raise this warning that we should consider adding this filter to?

[bdg221]

At this point there are two warnings, both PendingDeprecationWarning related to Qiskit deprecations.

/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pennylane_qiskit/qiskit_device.py:26: PendingDeprecationWarning: The qiskit.extensions module is pending deprecation since Qiskit 0.45.0. It will be deprecated in a following release, no sooner than 3 months after the 0.45.0 release.
    from qiskit import extensions as ex

mitiq/interface/mitiq_qiskit/tests/test_qiskit_utils.py: 42 warnings
mitiq/pec/representations/tests/test_learning.py: 594 warnings
mitiq/zne/tests/test_zne.py: 175 warnings
  /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/qiskit/utils/deprecation.py:183: PendingDeprecationWarning: Building a flow controller with keyword arguments is going to be deprecated. Custom controllers must be explicitly instantiated and appended to the task list.
    return func(*args, **kwargs)

[natestemen]

Oh yeah no need to worry about those! We have an issue to upgrade to qiskit 1.0 open #2204 that will hopefully resolve one/both of those warnings. Thanks for checking!