theme_region_wrapper-1.0.x-dev/theme_region_wrapper.install

<?php

/**
 * @file
 * Contains uninstall function for Theme region wrapper.
 */

/**
 * Implements hook_uninstall().
 */
function theme_region_wrapper_uninstall():void {
  $installed_themes = \Drupal::service('extension.list.theme')->getAllInstalledInfo();
  foreach ($installed_themes as $theme => $installed_theme) {
    \Drupal::configFactory()
      ->getEditable("$theme.settings")
      ->clear('third_party_settings.theme_region_wrapper')
      ->save(TRUE);
  }
}