Bump skylight from 6.0.1 to 6.0.4

Bumps [skylight](https://github.com/skylightio/skylight-ruby) from 6.0.1 to 6.0.4.
- [Changelog](https://github.com/skylightio/skylight-ruby/blob/master/CHANGELOG.md)
- [Commits](skylightio/skylight-ruby@v6.0.1...v6.0.4)

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

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

Gemfile.lock

@@ -433,7 +433,7 @@ GEM
     simplecov-html (0.12.3)
     simplecov-lcov (0.8.0)
     simplecov_json_formatter (0.1.4)
-    skylight (6.0.1)
+    skylight (6.0.4)
       activesupport (>= 5.2.0)
     slop (3.6.0)
     snaky_hash (2.0.1)