Issue #3279527: Ensure plugins are reloaded after an update

package_manager/tests/fixtures/updated_module/1.0.0/src/Plugin/Block/DeletedBlock.php

+<?php
+
+namespace Drupal\updated_module\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+
+/**
+ * This block is removed from version 1.1.0 of this module.
+ *
+ * @Block(
+ *   id = "updated_module_deleted_block",
+ *   admin_label = @Translation("Deleted block"),
+ * )
+ */
+class DeletedBlock extends BlockBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    return [
+      '#markup' => $this->t('Goodbye!'),
+    ];
+  }
+
+}