Bump docutils from 0.16 to 0.21.2

Bumps [docutils](https://docutils.sourceforge.io) from 0.16 to 0.21.2.

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

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

setup.cfg

@@ -61,7 +61,7 @@ python_requires = >= 3.9
 [options.extras_require]
 dev =
     black
-    docutils==0.16
+    docutils==0.21.2
     flake8
     flake8-bugbear
     flake8-docstrings