Fix autoload path mutations

Autoload paths are frozen when Zeitwerk is loaded so these are
failing.

We wouldn't need to add these paths anyway when we're booting the
whole Rails app since these are already there. So these should be
fine to skip.

spec/fast_spec_helper.rb

@@ -11,6 +11,9 @@ require_relative '../config/settings'
 require_relative 'support/rspec'
 require 'active_support/all'
 
-ActiveSupport::Dependencies.autoload_paths << 'lib'
-ActiveSupport::Dependencies.autoload_paths << 'ee/lib'
+unless ActiveSupport::Dependencies.autoload_paths.frozen?
+  ActiveSupport::Dependencies.autoload_paths << 'lib'
+  ActiveSupport::Dependencies.autoload_paths << 'ee/lib'
+end
+
 ActiveSupport::XmlMini.backend = 'Nokogiri'

spec/services/service_response_spec.rb

 # frozen_string_literal: true
 
 require 'fast_spec_helper'
-
-ActiveSupport::Dependencies.autoload_paths << 'app/services'
+require_relative '../../app/services/service_response'
 
 describe ServiceResponse do
   describe '.success' do