[rails] disable eager loading in make_basic_app

sentry-rails/spec/dummy/test_rails_app/app.rb

@@ -56,7 +56,7 @@ def self.name
   app.config.hosts = nil
   app.config.secret_key_base = "test"
   app.config.logger = ActiveSupport::Logger.new(nil)
-  app.config.eager_load = true
+  app.config.eager_load = false
   app.config.active_job.queue_adapter = :test
 
   # Eager load namespaces can be accumulated after repeated initializations and make initialization