Remove unused query parameters in redirect

These actions are never called with query parameters in our application,
so there's no need to use these parameters in a redirect.

Note in the test I'm using the `get` method because the `patch` method
wouldn't send query parameters. This doesn't mean the action can be
accessed through GET requests, since controller tests don't check route
verbs.

app/controllers/debates_controller.rb

@@ -37,12 +37,12 @@ class DebatesController < ApplicationController
 
   def unmark_featured
     @debate.update!(featured_at: nil)
-    redirect_to request.query_parameters.merge(action: :index)
+    redirect_to debates_path
   end
 
   def mark_featured
     @debate.update!(featured_at: Time.current)
-    redirect_to request.query_parameters.merge(action: :index)
+    redirect_to debates_path
   end
 
   def disable_recommendations