build(deps): bump json from 2.20.0 to 2.21.1 in /docs/v3 (#5333)

Bumps [json](https://github.com/ruby/json) from 2.20.0 to 2.21.1.
- [Release notes](https://github.com/ruby/json/releases)
- [Changelog](https://github.com/ruby/json/blob/master/CHANGES.md)
- [Commits](ruby/json@v2.20.0...v2.21.1)

---
updated-dependencies:
- dependency-name: json
  dependency-version: 2.21.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

docs/v3/Gemfile.lock

@@ -51,7 +51,7 @@ GEM
     http_parser.rb (0.8.1)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
-    json (2.20.0)
+    json (2.21.1)
     kramdown (2.5.2)
       rexml (>= 3.4.4)
     libv8-node (24.12.0.1-arm64-darwin)