Remove the password hint details in drupal register page

You can use the below code remove the password hint details in drupal register page.

/**
 * Implements hook_element_info_alter().
 */
function HOOK_element_info_alter(&$types) {
  if (isset($types['password_confirm']['#process']) && (($position = array_search('user_form_process_password_confirm', $types['password_confirm']['#process'])) !== FALSE)) {
    unset($types['password_confirm']['#process'][$position]);
  }
}

Note: Please clear form cache after adding