Change migration to be reversible if needed

Author: jamiebenstead

db/migrate/20260323152328_update_creator_id_index_on_schools.rb

@@ -1,5 +1,5 @@
 class UpdateCreatorIdIndexOnSchools < ActiveRecord::Migration[7.2]
-  def change
+  def up
     remove_index :schools, name: "index_schools_on_creator_id"
 
     add_index :schools,
@@ -8,4 +8,13 @@ def change
               where: "rejected_at IS NULL",
               name: "index_schools_on_creator_id_active_only"
   end
-end
+
+  def down
+    remove_index :schools, name: "index_schools_on_creator_id_active_only"
+
+    add_index :schools,
+              :creator_id,
+              unique: true,
+              name: "index_schools_on_creator_id"
+  end
+end