Bump pygments from 2.10.0 to 2.15.0

Bumps [pygments](https://github.com/pygments/pygments) from 2.10.0 to 2.15.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.10.0...2.15.0)

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

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

requirements.txt

@@ -29,7 +29,7 @@ mkdocs==1.2.3; python_version >= '3.6'
 mkdocstrings-crystal==0.3.4
 mkdocstrings==0.16.2
 packaging==21.3; python_version >= '3.6'
-pygments==2.10.0; python_version >= '3.5'
+pygments==2.15.0; python_version >= '3.5'
 pymdown-extensions==9.1; python_version >= '3.6'
 pyparsing==3.0.6; python_version >= '3.6'
 python-dateutil==2.8.2; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2'