Bump pandas-stubs from 2.1.1.230928 to 2.1.4.231218

Bumps [pandas-stubs](https://github.com/pandas-dev/pandas-stubs) from 2.1.1.230928 to 2.1.4.231218.
- [Changelog](https://github.com/pandas-dev/pandas-stubs/blob/main/docs/release_procedure.md)
- [Commits](pandas-dev/pandas-stubs@v2.1.1.230928...v2.1.4.231218)

---
updated-dependencies:
- dependency-name: pandas-stubs
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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