Bump nokogiri from 1.12.5 to 1.13.4

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.12.5 to 1.13.4.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/v1.13.4/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.12.5...v1.13.4)

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

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

Gemfile.lock

@@ -114,7 +114,7 @@ GEM
     minitest (5.14.4)
     msgpack (1.4.2)
     nio4r (2.5.8)
-    nokogiri (1.12.5-x86_64-linux)
+    nokogiri (1.13.4-x86_64-linux)
       racc (~> 1.4)
     oauth (0.5.6)
     omniauth (2.0.4)