Bump docutils from 0.17.1 to 0.21.2

Bumps [docutils](https://docutils.sourceforge.io) from 0.17.1 to 0.21.2.

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

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

pyproject.toml

@@ -46,7 +46,7 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 docs = [
-	"docutils==0.17.1",               # https://jupyterbook.org/en/stable/content/citations.html?highlight=docutils#citations-and-bibliographies
+	"docutils==0.21.2",               # https://jupyterbook.org/en/stable/content/citations.html?highlight=docutils#citations-and-bibliographies
 	"jupyter-book>=0.15.1",
 	"sphinxcontrib-apidoc>=0.4.0,<1",
 ]