fix test

Author: Maxim Solovev

tests/Unit/DependencyInjection/HttplugExtensionTest.php

@@ -184,7 +184,6 @@ public function testClientPlugins(): void
             'httplug.client.acme.authentication.my_basic',
             'httplug.client.acme.plugin.cache',
             'httplug.client.acme.plugin.error',
-            'httplug.client.acme.plugin.throttle',
         ];
         $pluginReferences = array_map(function ($id) {
             return new Reference($id);