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

spec/controllers/debates_controller_spec.rb

@@ -50,4 +50,15 @@ describe DebatesController do
       end.not_to change { debate.reload.votes_for.size }
     end
   end
+
+  describe "PUT mark_featured" do
+    it "ignores query parameters" do
+      debate = create(:debate)
+      sign_in create(:administrator).user
+
+      get :mark_featured, params: { id: debate, controller: "proposals" }
+
+      expect(response).to redirect_to debates_path
+    end
+  end
 end