Remove old ln columns from users table

db/migrate/20250506154628_remove_ln_fields_from_users.rb

@@ -0,0 +1,6 @@
+class RemoveLnFieldsFromUsers < ActiveRecord::Migration[8.0]
+  def change
+    remove_column :users, :ln_account
+    remove_column :users, :ln_password_ciphertext
+  end
+end