Bump nokogiri from 1.10.4 to 1.13.4

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.4 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@v1.10.4...v1.13.4)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -44,10 +44,12 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     method_source (0.9.2)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.8.0)
     minitest (5.11.3)
-    nokogiri (1.10.4)
-      mini_portile2 (~> 2.4.0)
+    nokogiri (1.13.4)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
+    racc (1.6.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)