Bump jupyter-sphinx from 0.4.0 to 0.5.3

Bumps [jupyter-sphinx](https://github.com/jupyter/jupyter-sphinx) from 0.4.0 to 0.5.3.
- [Release notes](https://github.com/jupyter/jupyter-sphinx/releases)
- [Changelog](https://github.com/jupyter/jupyter-sphinx/blob/main/RELEASE.md)
- [Commits](jupyter/jupyter-sphinx@v0.4.0...v0.5.3)

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

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