Bump rubocop from 1.8.1 to 1.9.0

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 1.8.1 to 1.9.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v1.8.1...v1.9.0)

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

Gemfile

@@ -52,7 +52,7 @@ end
 group :development, :test do
   gem 'byebug'
   gem 'listen'
-  gem 'rubocop', '~> 1.8', require: false
+  gem 'rubocop', '~> 1.9', require: false
 end
 
 group :test do

Gemfile.lock

@@ -75,7 +75,7 @@ GEM
       zeitwerk (~> 2.2, >= 2.2.2)
     acts_as_list (1.0.3)
       activerecord (>= 4.2)
-    ast (2.4.1)
+    ast (2.4.2)
     autoprefixer-rails (10.1.0.0)
       execjs
     backport (1.1.2)
@@ -237,7 +237,7 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.10.0)
     rspec-support (3.10.1)
-    rubocop (1.8.1)
+    rubocop (1.9.0)
       parallel (~> 1.10)
       parser (>= 3.0.0.0)
       rainbow (>= 2.2.2, < 4.0)
@@ -246,7 +246,7 @@ GEM
       rubocop-ast (>= 1.2.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.4.0)
+    rubocop-ast (1.4.1)
       parser (>= 2.7.1.5)
     ruby-progressbar (1.11.0)
     safe_yaml (1.0.5)
@@ -354,7 +354,7 @@ DEPENDENCIES
   rails-dom-testing (~> 2.0.0)
   rails_autolink
   rspec-expectations
-  rubocop (~> 1.8)
+  rubocop (~> 1.9)
   sanitize (~> 5.2)
   sassc-rails (~> 2.1.2)
   simplecov