Bump nokogiri from 1.13.10 to 1.15.4

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.13.10 to 1.15.4.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.13.10...v1.15.4)

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

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

Gemfile.lock

@@ -211,8 +211,8 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.20.0)
     multipart-post (2.3.0)
-    nokogiri (1.13.10)
-      mini_portile2 (~> 2.8.0)
+    nokogiri (1.15.4)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     octokit (4.22.0)
       faraday (>= 0.9)