Fix failing API tests on Ruby 2.7 after migration to Rails 7.1 (#36320, #39760).

Patch by @maeda-m.

git-svn-id: https://svn.redmine.org/redmine/trunk@22509 e93f8b46-1217-0410-a6f0-8f06a7374b81

config/initializers/10-patches.rb

@@ -148,8 +148,10 @@ module ActionView
       super values
     end
   end)
+end
 
-  Rendering.prepend(Module.new do
+module ActionController
+  Base.prepend(Module.new do
     def rendered_format
       if lookup_context.formats.first == :api
         return request.format