fix(subscriptions): reply notifications not working (#3445)

* chore: subscriptions backend test infrastructure

* test: reply notification

* fix: fix reply notifications not working

extensions/subscriptions/tests/integration/setup.php

@@ -0,0 +1,16 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+use Flarum\Testing\integration\Setup\SetupScript;
+
+require __DIR__.'/../../vendor/autoload.php';
+
+$setup = new SetupScript();
+
+$setup->run();