Bump nokogiri from 1.19.1 to 1.19.4 in /docs

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.19.1 to 1.19.4.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.19.1...v1.19.4)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-version: 1.19.4
  dependency-type: indirect
...

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

Author: dependabot[bot]

docs/Gemfile.lock

@@ -92,7 +92,7 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.24.1)
     mutex_m (0.2.0)
-    nokogiri (1.19.1-x86_64-linux-gnu)
+    nokogiri (1.19.4-x86_64-linux-gnu)
       racc (~> 1.4)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)