Merge branch '6.4' into 7.1

* 6.4:
  [DoctrineBridge] Fix Connection::createSchemaManager() for Doctrine DBAL v2
  [HttpClient] Various cleanups after recent changes
  do not add child nodes to EmptyNode instances
  consider write property visibility to decide whether a property is writable
  add comment explaining why HttpClient tests are run separately
  silence warnings issued by Redis Sentinel on connection issues

Transport/Connection.php

@@ -140,7 +140,7 @@ public function __construct(array $options, \Redis|Relay|\RedisCluster|null $red
                                     'readTimeout' => $options['read_timeout'],
                                 ];
 
-                                $sentinel = new \RedisSentinel($params);
+                                $sentinel = @new \RedisSentinel($params);
                             } else {
                                 $sentinel = @new $sentinelClass($host, $port, $options['timeout'], $options['persistent_id'], $options['retry_interval'], $options['read_timeout']);
                             }