build(deps): [security] bump json from 2.1.0 to 2.4.1

Bumps [json](https://github.com/flori/json) from 2.1.0 to 2.4.1. **This update includes a security fix.**
- [Release notes](https://github.com/flori/json/releases)
- [Changelog](https://github.com/flori/json/blob/master/CHANGES.md)
- [Commits](flori/json@v2.1.0...v2.4.1)

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

Gemfile.lock

@@ -107,7 +107,7 @@ GEM
     jbuilder (2.8.0)
       activesupport (>= 4.2.0)
       multi_json (>= 1.2)
-    json (2.1.0)
+    json (2.4.1)
     launchy (2.4.3)
       addressable (~> 2.3)
     letter_opener (1.7.0)