Bump pygments from 2.17.2 to 2.18.0 in /docs

Bumps [pygments](https://github.com/pygments/pygments) from 2.17.2 to 2.18.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.17.2...2.18.0)

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

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

docs/requirements.txt

@@ -1,6 +1,6 @@
 Jinja2==3.1.3
 MarkupSafe==2.1.5
-Pygments==2.17.2
+Pygments==2.18.0
 alabaster==0.7.16
 babel==2.14.0
 certifi==2024.2.2