Issue #3364958: Stages should be destroyed in the background, during cron runs

package_manager/src/Cleaner.php

+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\package_manager;
+
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\File\FileSystemInterface;
+use Drupal\Core\State\StateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+final class Cleaner implements ContainerInjectionInterface {
+
+  private const STATE_KEY = 'package_manager_clean';
+
+  public function __construct(
+    private readonly StateInterface $state,
+    private readonly FileSystemInterface $fileSystem,
+  ) {}
+
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get(StateInterface::class),
+      $container->get(FileSystemInterface::class),
+    );
+  }
+
+  public static function addDirectory(string $dir): void {
+    \Drupal::state()->set(static::STATE_KEY, $dir);
+  }
+
+  public function hookCron(): void {
+    $staging_root = $this->state->get(static::STATE_KEY);
+    if ($staging_root && file_exists($staging_root)) {
+      $this->fileSystem->deleteRecursive($staging_root, function (string $path): void {
+        $this->fileSystem->chmod($path, 0777);
+      });
+    }
+  }
+
+}