Bump pygments from 2.5.2 to 2.6.1

Bumps [pygments](https://github.com/pygments/pygments) from 2.5.2 to 2.6.1.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.5.2...2.6.1)

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

Author: dependabot-preview[bot]

dev-requirements.txt

@@ -1,7 +1,7 @@
 # We use dev-requirements.txt instead of just declaring the requirements here
 # because Read The Docs needs a requirements file.
 PyYAML==5.3
-Pygments==2.5.2
+Pygments==2.6.1
 Sphinx-Substitution-Extensions==2020.2.21.0
 Sphinx==2.4.4
 VWS-Python-Mock==2019.12.27.0