[TST not for merge] test with pandas 3.0 rc

[jorisvandenbossche]

PR Description

Testing with pandas 3.0 rc, see #1546 for context. I ran the tests locally, but pushing the changes I made to the pixi config to show how I did that / also check this in the CI to illustrate the current failures.

PR Checklist

Please ensure that you have done the following:

1. PR in from a fork off your branch. Do not PR from <your_username>:dev, but rather from <your_username>:<feature-branch_name>.

2. If you're not on the contributors list, add yourself to AUTHORS.md.

3. Add a line to CHANGELOG.md under the latest version header (i.e. the one that is "on deck") describing the contribution.
   • Do use some discretion here; if there are multiple PRs that are related, keep them in a single line.

Automatic checks

There will be automatic checks run on the PR. These include:

• Building a preview of the docs on Netlify
• Automatically linting the code
• Making sure the code is documented
• Making sure that all tests are passed
• Making sure that code coverage doesn't go down.

Relevant Reviewers

Please tag maintainers to review.

• @ericmjl

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.56%. Comparing base (901f4b3) to head (6975697).
⚠️ Report is 11 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #1547   +/-   ##
=======================================
  Coverage   87.56%   87.56%           
=======================================
  Files          95       95           
  Lines        6819     6819           
=======================================
  Hits         5971     5971           
  Misses        848      848           

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