Bump pygments from 2.18.0 to 2.20.0 in /docs

Bumps [pygments](https://github.com/pygments/pygments) from 2.18.0 to 2.20.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.18.0...2.20.0)

---
updated-dependencies:
- dependency-name: pygments
  dependency-version: 2.20.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -61,7 +61,7 @@ pathspec==0.12.1
     #   mkdocs-macros-plugin
 platformdirs==4.3.6
     # via mkdocs-get-deps
-pygments==2.18.0
+pygments==2.20.0
     # via
     #   -r requirements.in
     #   mkdocs-material