Change unauthenticated responses to be cached in REST API (#24348)

app/controllers/api/v2/instances_controller.rb

@@ -2,7 +2,7 @@
 
 class Api::V2::InstancesController < Api::V1::InstancesController
   def show
-    expires_in 3.minutes, public: true
+    cache_even_if_authenticated!
     render_with_cache json: InstancePresenter.new, serializer: REST::InstanceSerializer, root: 'instance'
   end
 end