Bump mini_racer from 0.3.1 to 0.4.0 (#2468)

Bumps [mini_racer](https://github.com/discourse/mini_racer) from 0.3.1 to 0.4.0.
- [Release notes](https://github.com/discourse/mini_racer/releases)
- [Changelog](https://github.com/rubyjs/mini_racer/blob/master/CHANGELOG)
- [Commits](https://github.com/discourse/mini_racer/compare/v0.3.1...v0.4.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile

@@ -33,7 +33,7 @@ gem 'slim', '>= 2.0', require: false
 gem 'rubydns', '~> 2.0.2', require: false
 
 # For less, note there is no compatible JS runtime for windows
-gem 'mini_racer', '~> 0.3.1', platforms: :ruby
+gem 'mini_racer', '~> 0.4.0', platforms: :ruby
 gem 'therubyrhino', '>= 2.0', platforms: :jruby
 
 # Code Quality

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
     kramdown (2.3.1)
       rexml
     lazy_priority_queue (0.1.1)
-    libv8 (8.4.255.0)
+    libv8-node (15.14.0.1)
     liquid (5.0.1)
     listen (3.4.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
@@ -144,8 +144,8 @@ GEM
     middleware (0.1.0)
     mini_mime (1.0.2)
     mini_portile2 (2.5.0)
-    mini_racer (0.3.1)
-      libv8 (~> 8.4.255)
+    mini_racer (0.4.0)
+      libv8-node (~> 15.14.0.0)
     minitest (5.14.3)
     multi_test (0.1.2)
     mustermann (1.1.1)
@@ -281,7 +281,7 @@ DEPENDENCIES
   liquid (>= 3.0)
   middleman-cli!
   middleman-core!
-  mini_racer (~> 0.3.1)
+  mini_racer (~> 0.4.0)
   pry
   pry-rescue
   pry-stack_explorer