Dereference the format type before template construction

The format should always be exactly one symbol.  Now we don't need to
check whether or not the format is a `Type` in the constructor.

actionview/lib/action_view/template.rb

@@ -149,7 +149,7 @@ module ActionView
       end
 
       @updated_at        = details[:updated_at] || Time.now
-      @formats           = Array(format).map { |f| f.respond_to?(:ref) ? f.ref : f  }
+      @formats           = Array(format)
       @variants          = [details[:variant]]
       @compile_mutex     = Mutex.new
     end

actionview/lib/action_view/template/resolver.rb

@@ -300,7 +300,7 @@ module ActionView
         handler = Template.handler_for_extension(extension)
         format, variant = pieces.last.split(EXTENSIONS[:variants], 2) if pieces.last
         format = if format
-          Template::Types[format]
+          Template::Types[format]&.ref
         else
           if handler.respond_to?(:default_format) # default_format can return nil
             handler.default_format