Bump web-console from 3.7.0 to 4.0.4

We were getting a warning after upgrading to Rails 6:

DEPRECATION WARNING: ActionView::Base instances should be constructed
with a lookup context, assignments, and a controller.

We didn't upgrade web-console earlier because version 4.x isn't
compatible with Rails 5.

Gemfile

@@ -113,7 +113,7 @@ group :development do
   gem "rubocop-rspec", "~> 2.4.0", require: false
   gem "rvm1-capistrano3", "~> 1.4.0", require: false
   gem "scss_lint", "~> 0.59.0", require: false
-  gem "web-console", "~> 3.7.0"
+  gem "web-console", "~> 4.0.4"
 end
 
 eval_gemfile "./Gemfile_custom"

Gemfile.lock

@@ -680,11 +680,11 @@ GEM
       addressable
       httpi (~> 2.0)
       nokogiri (>= 1.4.2)
-    web-console (3.7.0)
-      actionview (>= 5.0)
-      activemodel (>= 5.0)
+    web-console (4.0.4)
+      actionview (>= 6.0.0)
+      activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
-      railties (>= 5.0)
+      railties (>= 6.0.0)
     webdrivers (4.6.0)
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
@@ -803,7 +803,7 @@ DEPENDENCIES
   uglifier (~> 4.2.0)
   uuidtools (~> 2.1.5)
   view_component (~> 2.49.1)
-  web-console (~> 3.7.0)
+  web-console (~> 4.0.4)
   webdrivers (~> 4.6.0)
   whenever (~> 1.0.0)
   wicked_pdf (~> 2.1.0)