⬆️ Bump pygments from 2.8.1 to 2.15.0 in /server/configs

Bumps [pygments](https://github.com/pygments/pygments) from 2.8.1 to 2.15.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.8.1...2.15.0)

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

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

Author: dependabot[bot]

server/configs/requirements.txt

@@ -18,7 +18,7 @@ Jinja2==2.11.3
 markupsafe==2.0.1
 coreapi==2.3.3
 Markdown==3.3.4
-Pygments==2.8.1
+Pygments==2.15.0
 
 #for django permission
 django-guardian==2.3.0