Bump pygments from 2.7.2 to 2.7.4
Bump pygments from 2.7.2 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.7.2 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](https://github.com/pygments/pygments/compare/2.7.2...2.7.4)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
City-of-Helsinki/linkedevents,City-of-Helsinki/linkedevents,City-of-Helsinki/linkedevents