Bump nokogiri from 1.15.5 to 1.16.4 in /test_app

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.15.5 to 1.16.4.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.15.5...v1.16.4)

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

Signed-off-by: dependabot[bot] <[email protected]>

test_app/Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    administrate-field-active_storage (0.4.1)
+    administrate-field-active_storage (1.0.2)
       administrate (>= 0.2.2)
       rails (>= 7.0)
 
@@ -172,11 +172,11 @@ GEM
     net-smtp (0.4.0)
       net-protocol
     nio4r (2.6.0)
-    nokogiri (1.15.5-arm64-darwin)
+    nokogiri (1.16.4-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.15.5-x86_64-darwin)
+    nokogiri (1.16.4-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.15.5-x86_64-linux)
+    nokogiri (1.16.4-x86_64-linux)
       racc (~> 1.4)
     psych (5.1.1.1)
       stringio