Deps: Bump pygments in /backport-pull-request in the dependencies group

Bumps the dependencies group in /backport-pull-request with 1 update: [pygments](https://github.com/pygments/pygments).


Updates `pygments` from 2.17.2 to 2.18.0
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.17.2...2.18.0)

---
updated-dependencies:
- dependency-name: pygments
  dependency-type: indirect
  update-type: version-update:semver-minor
  dependency-group: dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>