fix: shaky test due to pandas version dependency

[alanprior]

Issue

Please link the corresponding GitHub issue. If an issue does not already exist,
please open one to describe the bug or feature request before creating a pull request.

This allows us to discuss the proposal and helps avoid unnecessary work.

Motivation and Context

We are fixing a shaky test that was affected by different behavior of pandas v3.

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Public API Changes

• [X ] No Public API changes
• Yes, Public API changes (Details below)

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How Has This Been Tested?

This is a test fix.

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Checklist

• [ X] The changes have been tested locally.
• [ X] Documentation has been updated (if the public API or usage changes).
• [ X] A changelog entry has been added (see changelog/README.md), or "no changelog needed" label requested.
• [X ] The code follows the project's style guidelines.
• [ X] I have considered the impact of these changes on the public API.

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[gemini-code-assist]

Code Review

This pull request addresses a flaky test caused by a dependency on the pandas version. The change correctly updates the test data to ensure consistent behavior across different pandas versions by accounting for how None and np.nan are handled. The fix is appropriate and the explanatory comment is helpful. I have one suggestion to make the test even more robust.

[jmetzen-pl]

Thanks for porting this to public (will do the same in the future)!

[psinger-prior]

lgtm! thx