Bump nokogiri from 1.18.8 to 1.18.9 in /docs (#4466)

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.18.8 to 1.18.9.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.18.8...v1.18.9)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-version: 1.18.9
  dependency-type: indirect
...

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

Author: dependabot[bot]