chore: bump sphinx from 7.1.2 to 8.1.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.1.2 to 8.1.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.1.2...v8.1.3)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -37,7 +37,7 @@ ipython = "^8.28.0"
 polars = ["polars"]
 
 [tool.poetry.dev-dependencies]
-Sphinx = "~7.1"
+Sphinx = "~8.1"
 coverage = "^7.6.0"
 darglint = "^1.8.1"
 mypy = "^1.12"