chore(deps): bump github-slugger, remove useless `@types/github-slugger` (#11987)

* chore(deps): bump github-slugger and @types/github-slugger

Bumps [github-slugger](https://github.com/Flet/github-slugger) and [@types/github-slugger](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/github-slugger). These dependencies needed to be updated together.

Updates `github-slugger` from 1.5.0 to 2.0.0
- [Release notes](https://github.com/Flet/github-slugger/releases)
- [Changelog](https://github.com/Flet/github-slugger/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Flet/github-slugger/compare/v1.5.0...2.0.0)

Updates `@types/github-slugger` from 1.3.0 to 2.0.0
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/github-slugger)

---
updated-dependencies:
- dependency-name: "@types/github-slugger"
  dependency-version: 2.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
- dependency-name: github-slugger
  dependency-version: 2.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

* remove useless types

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: sebastien <lorber.sebastien@gmail.com>