Filter pandas deprecation warning

[dstansby]

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PR Description

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (cda26e4) 94.64% compared to head (a6ccc51) 94.64%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #114 +/- ## ======================================= Coverage 94.64% 94.64% ======================================= Files 6 6 Lines 280 280 ======================================= Hits 265 265 Misses 15 15 ```

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