Bump json from 2.7.5 to 2.7.6

Bumps [json](https://github.com/ruby/json) from 2.7.5 to 2.7.6.
- [Release notes](https://github.com/ruby/json/releases)
- [Changelog](https://github.com/ruby/json/blob/master/CHANGES.md)
- [Commits](ruby/json@v2.7.5...v2.7.6)

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

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

Gemfile.lock

@@ -144,7 +144,7 @@ GEM
     jbuilder (2.13.0)
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
-    json (2.7.5)
+    json (2.7.6)
     logger (1.6.1)
     loofah (2.23.1)
       crass (~> 1.0.2)