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] <[email protected]>

Gemfile.lock

@@ -235,7 +235,7 @@ GEM
     mini_magick (3.8.1)
       subexec (~> 0.2.1)
     mini_mime (1.1.2)
-    mini_portile2 (2.6.1)
+    mini_portile2 (2.8.0)
     minitest (5.14.4)
     multi_json (1.15.0)
     multi_xml (0.6.0)
@@ -245,8 +245,8 @@ GEM
       net-ssh (>= 2.6.5, < 7.0.0)
     net-ssh (6.1.0)
     netaddr (1.5.1)
-    nokogiri (1.12.5)
-      mini_portile2 (~> 2.6.1)
+    nokogiri (1.13.4)
+      mini_portile2 (~> 2.8.0)
       racc (~> 1.4)
     notiffany (0.1.3)
       nenv (~> 0.1)