⬆️ Update pydata-sphinx-theme requirement

Updates the requirements on [pydata-sphinx-theme](https://github.com/pydata/pydata-sphinx-theme) to permit the latest version.
- [Release notes](https://github.com/pydata/pydata-sphinx-theme/releases)
- [Changelog](https://github.com/pydata/pydata-sphinx-theme/blob/main/RELEASE.md)
- [Commits](pydata/pydata-sphinx-theme@v0.15.2...v0.16.0)

---
updated-dependencies:
- dependency-name: pydata-sphinx-theme
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -52,7 +52,7 @@ testing-no-myst = [
 ]
 
 theme-furo = ["furo~=2024.7.18"]
-theme-pydata = ["pydata-sphinx-theme~=0.15.2"]
+theme-pydata = ["pydata-sphinx-theme>=0.15.2,<0.17.0"]
 theme-rtd = ["sphinx-rtd-theme~=2.0"]
 theme-sbt = ["sphinx-book-theme~=1.1"]
 theme-im = ["sphinx-immaterial~=0.12.2"]