Add archived_lettings if it's not defined in json

app/models/form_handler.rb

@@ -101,6 +101,9 @@ class FormHandler
     if forms["previous_lettings"].blank? && current_collection_start_year >= 2022
       forms["previous_lettings"] = Form.new(nil, previous_collection_start_year, LETTINGS_SECTIONS, "lettings")
     end
+    if forms["archived_lettings"].blank? && current_collection_start_year >= 2025
+      forms["archived_lettings"] = Form.new(nil, previous_collection_start_year - 1, LETTINGS_SECTIONS, "lettings")
+    end
     forms["current_lettings"] = Form.new(nil, current_collection_start_year, LETTINGS_SECTIONS, "lettings") if forms["current_lettings"].blank?
     forms["next_lettings"] = Form.new(nil, next_collection_start_year, LETTINGS_SECTIONS, "lettings") if forms["next_lettings"].blank?