Make change_type nullable in organisation name changes table

db/migrate/20250409113321_create_organisation_name_changes.rb

@@ -3,7 +3,7 @@ class CreateOrganisationNameChanges < ActiveRecord::Migration[7.2]
     create_table :organisation_name_changes do |t|
       t.references :organisation, null: false, foreign_key: true
       t.string :name, null: false
-      t.integer :change_type, null: false
+      t.integer :change_type
       t.date :startdate, null: false
       t.datetime :discarded_at
 

db/schema.rb

@@ -500,7 +500,7 @@ ActiveRecord::Schema[7.2].define(version: 2025_03_05_092900) do
   create_table "organisation_name_changes", force: :cascade do |t|
     t.bigint "organisation_id", null: false
     t.string "name", null: false
-    t.integer "change_type", null: false
+    t.integer "change_type"
     t.date "startdate", null: false
     t.datetime "discarded_at"
     t.datetime "created_at", null: false