Maintenance: Bump autoprefixer-rails from 10.3.3.0 to 10.4.0.0

Bumps [autoprefixer-rails](https://github.com/ai/autoprefixer-rails) from 10.3.3.0 to 10.4.0.0.
- [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/commits/10.4.0.0)

Gemfile.lock

@@ -114,7 +114,7 @@ GEM
       async
     async-pool (0.3.9)
       async (>= 1.25)
-    autoprefixer-rails (10.3.3.0)
+    autoprefixer-rails (10.4.0.0)
       execjs (~> 2)
     binding_of_caller (1.0.0)
       debug_inspector (>= 0.0.1)