Bump autoprefixer-rails from 8.2.0 to 9.1.4

Bumps [autoprefixer-rails](https://github.com/ai/autoprefixer-rails) from 8.2.0 to 9.1.4.
- [Release notes](https://github.com/ai/autoprefixer-rails/releases)
- [Changelog](https://github.com/ai/autoprefixer-rails/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ai/autoprefixer-rails/compare/8.2.0...9.1.4)

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

Gemfile

@@ -6,7 +6,7 @@ gem 'acts-as-taggable-on', '~> 5.0.0'
 gem 'acts_as_votable', '~> 0.11.1'
 gem 'ahoy_matey', '~> 1.6.0'
 gem 'ancestry', '~> 3.0.1'
-gem 'autoprefixer-rails', '~> 8.2.0'
+gem 'autoprefixer-rails', '~> 9.1.4'
 gem 'browser', '~> 2.5.2'
 gem 'cancancan', '~> 2.1.2'
 gem 'ckeditor', '~> 4.2.3'

Gemfile.lock

@@ -61,7 +61,7 @@ GEM
       activerecord (>= 3.2.0)
     arel (6.0.4)
     ast (2.4.0)
-    autoprefixer-rails (8.2.0)
+    autoprefixer-rails (9.1.4)
       execjs
     babel-source (5.8.35)
     babel-transpiler (0.7.0)
@@ -500,7 +500,7 @@ DEPENDENCIES
   acts_as_votable (~> 0.11.1)
   ahoy_matey (~> 1.6.0)
   ancestry (~> 3.0.1)
-  autoprefixer-rails (~> 8.2.0)
+  autoprefixer-rails (~> 9.1.4)
   browser (~> 2.5.2)
   bullet (~> 5.7.0)
   byebug (~> 10.0.0)