build(deps): bump pygments from 2.19.1 to 2.19.2 in /lib/spack/docs (spack#50927)

Bumps [pygments](https://github.com/pygments/pygments) from 2.19.1 to 2.19.2.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.19.1...2.19.2)

---
updated-dependencies:
- dependency-name: pygments
  dependency-version: 2.19.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

lib/spack/docs/requirements.txt

@@ -5,7 +5,7 @@ sphinx_design==0.6.1
 sphinx-rtd-theme==3.0.2
 python-levenshtein==0.27.1
 docutils==0.21.2
-pygments==2.19.1
+pygments==2.19.2
 urllib3==2.5.0
 pytest==8.4.1
 isort==6.0.1