chore(deps-dev): bump rubocop-rails from 2.21.1 to 2.21.2

Bumps [rubocop-rails](https://github.com/rubocop/rubocop-rails) from 2.21.1 to 2.21.2.
- [Release notes](https://github.com/rubocop/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-rails@v2.21.1...v2.21.2)

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

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

Gemfile.lock

@@ -189,7 +189,7 @@ GEM
       unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.29.0)
       parser (>= 3.2.1.0)
-    rubocop-rails (2.21.1)
+    rubocop-rails (2.21.2)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)
@@ -218,7 +218,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.8.2)
-    unicode-display_width (2.4.2)
+    unicode-display_width (2.5.0)
     vcr (6.2.0)
     webmock (3.19.1)
       addressable (>= 2.8.0)