Issue #3304365: Do not check excluded folders for symlinks

package_manager/src/Event/CollectIgnoredPathsEvent.php

+<?php
+
+namespace Drupal\package_manager\Event;
+
+use Drupal\package_manager\Stage;
+use PhpTuf\ComposerStager\Domain\Value\PathList\PathListInterface;
+use PhpTuf\ComposerStager\Infrastructure\Value\PathList\PathList;
+
+/**
+ * Defines an event that collects ignored paths.
+ *
+ * Ignored paths are completely ignored by Composer Stager. They are never
+ * copied into the staging area from the active directory, or vice-versa.
+ */
+class CollectIgnoredPathsEvent extends StageEvent implements PathListInterface {
+
+  /**
+   * The list of ignored paths.
+   *
+   * @var \PhpTuf\ComposerStager\Domain\Value\PathList\PathListInterface
+   */
+  protected PathListInterface $pathList;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(Stage $stage) {
+    parent::__construct($stage);
+    $this->pathList = new PathList([]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function add(array $paths): void {
+    $this->pathList->add($paths);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAll(): array {
+    return $this->pathList->getAll();
+  }
+
+}