Update nokogiri requirement from ~> 1.17.2 to ~> 1.18.1

Updates the requirements on [nokogiri](https://github.com/sparklemotion/nokogiri) to permit the latest version.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.17.2...v1.18.1)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-type: direct:production
...

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

Gemfile

@@ -5,7 +5,7 @@ source "https://rubygems.org"
 gemspec
 
 gem "gc_ruboconfig", "~> 5.0.2"
-gem "nokogiri", "~> 1.17.2"
+gem "nokogiri", "~> 1.18.1"
 gem "pry-byebug", "~> 3.10"
 gem "rspec", "~> 3.13"
 gem "rspec-github", "~> 2.4.0"