Build(deps): Bump diffy from 3.4.1 to 3.4.2 (#17167)

Bumps [diffy](https://github.com/samg/diffy) from 3.4.1 to 3.4.2.
- [Release notes](https://github.com/samg/diffy/releases)
- [Changelog](https://github.com/samg/diffy/blob/main/CHANGELOG)
- [Commits](https://github.com/samg/diffy/commits)

---
updated-dependencies:
- dependency-name: diffy
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

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

Gemfile.lock

@@ -107,7 +107,7 @@ GEM
       addressable
     debug_inspector (1.1.0)
     diff-lcs (1.5.0)
-    diffy (3.4.1)
+    diffy (3.4.2)
     digest (3.1.0)
     discourse-ember-rails (0.18.6)
       active_model_serializers