3337192: Removing modules using hook_post_update_NAME.

Closes #3337192

back_to_top.post_update.php

+<?php
+
+/**
+ * @file
+ * Post update functions for Back To Top.
+ * */
+
+/***
+ * Implementations of hook_post_update_NAME().
+ */
+
+/**
+ * Uninstall jquery ui, jquery ui effects modules.
+ */
+function back_to_top_post_update_uninstall_modules() {
+  /** @var \Drupal\Core\Extension\ModuleInstallerInterface $installer */
+  $installer = \Drupal::service('module_installer');
+  $installer->uninstall(['jquery_ui']);
+  $installer->uninstall(['jquery_ui_effects']);
+}