Bump nokogiri from 1.16.2 to 1.18.8 in /apps/y2bot

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.16.2 to 1.18.8.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.16.2...v1.18.8)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-version: 1.18.8
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

apps/y2bot/Gemfile.lock

@@ -50,16 +50,16 @@ GEM
     mutex_m (0.2.0)
     net-http (0.4.1)
       uri
-    nokogiri (1.16.2-arm64-darwin)
+    nokogiri (1.18.8-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.16.2-x86_64-linux)
+    nokogiri (1.18.8-x86_64-linux-gnu)
       racc (~> 1.4)
     parallel (1.24.0)
     parser (3.3.0.5)
       ast (~> 2.4.1)
       racc
     public_suffix (5.0.4)
-    racc (1.7.3)
+    racc (1.8.1)
     rainbow (3.1.1)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)