Merge pull request rails#50487 from nubinary/fix/unneccesary-readonly-attributes-to-a

Remove unnecessary to_a conversion for readonly_attributes method call

Author: kamipo

activerecord/lib/active_record/insert_all.rb

@@ -198,7 +198,7 @@ def to_sql
 
 
       def readonly_columns
-        primary_keys + model.readonly_attributes.to_a
+        primary_keys + model.readonly_attributes
       end
 
       def unique_by_columns