Bump docutils from 0.17 to 0.21.1

Bumps [docutils](https://docutils.sourceforge.io) from 0.17 to 0.21.1.

---
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

@@ -70,7 +70,7 @@ dev = [
 ]
 docs = [
     # We cannot update sphinx to >6 until docutils==0.20 is released: https://github.com/mcmtroffaes/sphinxcontrib-bibtex/issues/322
-    "docutils==0.17",
+    "docutils==0.21.1",
     "sphinx<6",
     "sphinx-autobuild",
     "nbsphinx",