bump pandas tests to run on 3.12

[davidhewitt]

Change Summary

Because it's now possible to run pandas on 3.12 tests, we should! Also this will be useful for me locally to debug the pandas failures in #1085

Related issue number

N/A

Checklist

• Unit tests for the changes exist
• Documentation reflects the changes where applicable
• Pydantic tests pass with this pydantic-core (except for expected changes)
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

[codecov]

Codecov Report

Merging #1097 (d3ead8b) into main (c7daf16) will not change coverage.
Report is 1 commits behind head on main.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1097   +/-   ##
=======================================
  Coverage   89.70%   89.70%           
=======================================
  Files         106      106           
  Lines       16359    16359           
  Branches       35       35           
=======================================
  Hits        14675    14675           
  Misses       1677     1677           
  Partials        7        7           

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[codspeed-hq]

CodSpeed Performance Report

Merging #1097 will not alter performance

_{Comparing dh/bump-pandas (d3ead8b) with main (c7daf16)}

Summary

✅ 140 untouched benchmarks

[sydney-runkle]

Fantastic! 🐼