build(deps): bump json from 2.9.0 to 2.9.1

Bumps [json](https://github.com/ruby/json) from 2.9.0 to 2.9.1.
- [Release notes](https://github.com/ruby/json/releases)
- [Changelog](https://github.com/ruby/json/blob/master/CHANGES.md)
- [Commits](ruby/json@v2.9.0...v2.9.1)

---
updated-dependencies:
- dependency-name: json
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -102,7 +102,7 @@ GEM
       jekyll (>= 3.7, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    json (2.9.0)
+    json (2.9.1)
     kramdown (2.5.1)
       rexml (>= 3.3.9)
     kramdown-parser-gfm (1.1.0)