build(deps-dev): bump gh-pages from 6.0.0 to 6.1.1 (#2136)

Bumps [gh-pages](https://github.com/tschaub/gh-pages) from 6.0.0 to 6.1.1.
- [Release notes](https://github.com/tschaub/gh-pages/releases)
- [Changelog](https://github.com/tschaub/gh-pages/blob/main/changelog.md)
- [Commits](tschaub/gh-pages@v6.0.0...v6.1.1)

---
updated-dependencies:
- dependency-name: gh-pages
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Mathieu Leplatre <mathieu@mozilla.com>