Fix typed override Hash defaults

The new merge options was not doing the correct thing when calling
`merge!` on `result`, since the result is now created as an indifferent
access hash, which doesn't seem to implement the block callback for
`merge!`.

This was causing the default `"activesupport" => "false"` setting to be
lost.

Instead we create a normal Hash and then convert it to an indifferent
access hash instead.

Author: paracycle

lib/tapioca/helpers/config_helper.rb

@@ -68,7 +68,7 @@ def config_options(options)
         .returns(Thor::CoreExt::HashWithIndifferentAccess)
     end
     def merge_options(*options)
-      options.each_with_object(Thor::CoreExt::HashWithIndifferentAccess.new) do |option, result|
+      merged = options.each_with_object({}) do |option, result|
         result.merge!(option || {}) do |_, this_val, other_val|
           if this_val.is_a?(Hash) && other_val.is_a?(Hash)
             Thor::CoreExt::HashWithIndifferentAccess.new(this_val.merge(other_val))
@@ -77,6 +77,8 @@ def merge_options(*options)
           end
         end
       end
+
+      Thor::CoreExt::HashWithIndifferentAccess.new(merged)
     end
   end
 end