chore(deps): bump pygments from 2.18.0 to 2.19.0 in /source

Bumps [pygments](https://github.com/pygments/pygments) from 2.18.0 to 2.19.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.18.0...2.19.0)

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

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

source/requirements.txt

@@ -184,7 +184,7 @@ pydata-sphinx-theme==0.13.1
     # via
     #   -r source/requirements.txt
     #   sphinx-book-theme
-pygments==2.18.0
+pygments==2.19.0
     # via
     #   -r source/requirements.txt
     #   accessible-pygments