Update sdoc to 2.3.0

With the migration of SDoc to a frameless layout, the URLs to assets
were made absolute instead of relative because of Turbolinks asset
tracking.  But absolute URLs fail when we have multiple versions of the
docs in subdirectories like: https://api.rubyonrails.org/v6.1/

This version of sdoc restores relative URLs by disabling the Turbolinks
asset tracking.

Fixes #44042

Gemfile

@@ -50,7 +50,7 @@ group :rubocop do
 end
 
 group :doc do
-  gem "sdoc", ">= 2.2.0"
+  gem "sdoc", ">= 2.3.0"
   gem "redcarpet", "~> 3.2.3", platforms: :ruby
   gem "w3c_validators", "~> 1.3.6"
   gem "kindlerb", "~> 1.2.0"

Gemfile.lock

@@ -458,8 +458,8 @@ GEM
     rubyzip (2.3.2)
     rufus-scheduler (3.6.0)
       fugit (~> 1.1, >= 1.1.6)
-    sdoc (2.2.0)
-      rdoc (>= 5.0)
+    sdoc (2.3.0)
+      rdoc (>= 5.0, < 6.4.0)
     selenium-webdriver (4.1.0)
       childprocess (>= 0.5, < 5.0)
       rexml (~> 3.2, >= 3.2.5)
@@ -620,7 +620,7 @@ DEPENDENCIES
   rubocop-packaging
   rubocop-performance
   rubocop-rails
-  sdoc (>= 2.2.0)
+  sdoc (>= 2.3.0)
   selenium-webdriver (>= 4.0.0)
   sequel
   sidekiq