Bump rubocop from 1.18.3 to 1.18.4

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.18.3 to 1.18.4.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop/compare/v1.18.3...v1.18.4)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -406,16 +406,16 @@ GEM
       rspec-mocks (~> 3.10)
       rspec-support (~> 3.10)
     rspec-support (3.10.2)
-    rubocop (1.18.3)
+    rubocop (1.18.4)
       parallel (~> 1.10)
       parser (>= 3.0.0.0)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml
-      rubocop-ast (>= 1.7.0, < 2.0)
+      rubocop-ast (>= 1.8.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.7.0)
+    rubocop-ast (1.8.0)
       parser (>= 3.0.1.1)
     rubocop-performance (1.11.4)
       rubocop (>= 1.7.0, < 2.0)