Add sign? methods to the Quote and CollectionItem models (#39047)

app/models/collection_item.rb

@@ -64,6 +64,10 @@ class CollectionItem < ApplicationRecord
     :featured_item
   end
 
+  def sign?
+    true
+  end
+
   private
 
   def set_position

app/models/quote.rb

@@ -79,6 +79,10 @@ class Quote < ApplicationRecord
     ActivityPub::QuoteRefreshWorker.perform_in(rand(REFRESH_DEADLINE), id)
   end
 
+  def sign?
+    true
+  end
+
   private
 
   def reset_parent_cache!