build(deps): bump docutils from 0.21.2 to 0.22.2 in /lib/spack/docs

Bumps [docutils](https://github.com/rtfd/recommonmark) from 0.21.2 to 0.22.2.
- [Changelog](https://github.com/readthedocs/recommonmark/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rtfd/recommonmark/commits)

---
updated-dependencies:
- dependency-name: docutils
  dependency-version: 0.22.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

lib/spack/docs/requirements.txt

@@ -6,7 +6,7 @@ sphinx-sitemap==2.8.0
 # fork of furo with a few changes that are not merged upstream
 git+https://github.com/haampie/furo.git@c1d161cb9e04b481ec3331db981aacfa132ecaa6#egg=furo
 python-levenshtein==0.27.1
-docutils==0.21.2
+docutils==0.22.2
 pygments==2.19.2
 urllib3==2.5.0
 pytest==8.4.2