Bump sphinx-design from 0.5.0 to 0.6.1

Bumps [sphinx-design](https://github.com/executablebooks/sphinx-design) from 0.5.0 to 0.6.1.
- [Release notes](https://github.com/executablebooks/sphinx-design/releases)
- [Changelog](https://github.com/executablebooks/sphinx-design/blob/main/CHANGELOG.md)
- [Commits](executablebooks/sphinx-design@v0.5.0...v0.6.1)

---
updated-dependencies:
- dependency-name: sphinx-design
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements/docs.txt

@@ -6,7 +6,7 @@ sphinx-rtd-theme>=1.0.0, <2.0.0
 myst-parser>=1.0, <3.0
 sphinxcontrib-apidoc>=0.3.0, <0.5.0
 nbsphinx>=0.8.5, <0.10.0
-sphinx_design==0.5.0  # Pinning for now as sphinx_design is v.new and still in flux.
+sphinx_design==0.6.1  # Pinning for now as sphinx_design is v.new and still in flux.
 ipykernel>=5.1.0, <7.0.0 # required for executing notebooks via nbsphinx
 ipython>=7.2.0, <9.0.0 # required for executing notebooks nbsphinx
 # dependencies required for imports to work and docs to render properly (as mocking doesn't work well)