Bump pygments from 2.8.1 to 2.9.0

Bumps [pygments](https://github.com/pygments/pygments) from 2.8.1 to 2.9.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](https://github.com/pygments/pygments/compare/2.8.1...2.9.0)

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

requirements.txt

@@ -4,7 +4,7 @@ flask-babel==2.0.0
 flask==1.1.2
 jinja2==2.11.3
 lxml==4.6.3
-pygments==2.8.1
+pygments==2.9.0
 python-dateutil==2.8.1
 pyyaml==5.4.1
 httpx[http2]==0.17.1