Update json requirement from < 3 to < 4

Updates the requirements on [json](https://github.com/ruby/json) to permit the latest version.
- [Release notes](https://github.com/ruby/json/releases)
- [Changelog](https://github.com/ruby/json/blob/master/CHANGES.md)
- [Commits](ruby/json@v1.1.8...v3.0.2)

---
updated-dependencies:
- dependency-name: json
  dependency-version: 3.0.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Gemfile

@@ -8,6 +8,6 @@ gem "rubocop", require: false
 gem "codeclimate-test-reporter"
 gem "concurrent-ruby", "< 1.3.9"
 # json 3.0 dropped the quirks_mode option that ActiveSupport 7.2.3.x still passes
-gem "json", "< 3"
+gem "json", "< 4"
 
 gem "rails", "~> #{ENV.fetch('RAILS_VERSION', '8.0')}"