Bump pygments from 2.7.1 to 2.7.2 (#5150)

Bumps [pygments](https://github.com/pygments/pygments) from 2.7.1 to 2.7.2.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.7.1...2.7.2)

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

requirements/doc.txt

@@ -1,5 +1,5 @@
 sphinx==3.2.1
 sphinxcontrib-asyncio==0.3.0
-pygments==2.7.1
+pygments==2.7.2
 aiohttp-theme==0.1.6
 sphinxcontrib-blockdiag==2.0.0