添加vendor扩展包

backend/vendor/symfony/cache/Exception/CacheException.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Exception;
+
+use Psr\Cache\CacheException as Psr6CacheInterface;
+use Psr\SimpleCache\CacheException as SimpleCacheInterface;
+
+if (interface_exists(SimpleCacheInterface::class)) {
+    class CacheException extends \Exception implements Psr6CacheInterface, SimpleCacheInterface
+    {
+    }
+} else {
+    class CacheException extends \Exception implements Psr6CacheInterface
+    {
+    }
+}