Install profiles no longer need to add an administrator role to user 1

Install profiles like Standard and Demo Umami used to contain code like:

  // Assign user 1 the "administrator" role.
  /** @var \Drupal\user\Entity\User $user */
  $user = User::load(1);
  $user->addRole('administrator');
  $user->save();

This is no longer necessary as the installer adds any admin roles created to user 1 as part of the Site configuration form submit handler.