Fixed bug that the parameter context on redis cluster cannot work when auth config isn't set or set with null value. (#7554)

Author: luizmanhani

src/RedisConnection.php

@@ -203,9 +203,7 @@ protected function createRedisCluster(): RedisCluster
             $parameters[] = $this->config['timeout'] ?? 0.0;
             $parameters[] = $this->config['cluster']['read_timeout'] ?? 0.0;
             $parameters[] = $this->config['cluster']['persistent'] ?? false;
-            if (isset($this->config['auth'])) {
-                $parameters[] = $this->config['auth'];
-            }
+            $parameters[] = $this->config['auth'] ?? null;
             if (! empty($this->config['cluster']['context'])) {
                 $parameters[] = $this->config['cluster']['context'];
             }