Bump nokogiri from 1.18.4 to 1.18.8 (#87)

Author: github-actions[bot]

Gemfile.lock

@@ -96,9 +96,9 @@ GEM
     mercenary (0.4.0)
     method_source (1.1.0)
     metrics (0.12.1)
-    nokogiri (1.18.4-arm64-darwin)
+    nokogiri (1.18.8-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.18.4-x86_64-linux-gnu)
+    nokogiri (1.18.8-x86_64-linux-gnu)
       racc (~> 1.4)
     parallel (1.26.3)
     parser (3.3.6.0)