chore(deps): 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@v0.15.4...v0.16.1)

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

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

pyproject.toml

@@ -24,7 +24,7 @@ classifiers = [
 ]
 dependencies = [
     "Sphinx>=4.2.0",
-    "pydata-sphinx-theme>=0.15.4,<0.16",
+    "pydata-sphinx-theme>=0.15.4,<0.17",
     "Jinja2>=3.1.2",
     "importlib-metadata>=4.0",
     "pdf2image>=1.17.0",