Merge branch '6.4' into 7.0

* 6.4:
  [TwigBridge] foundation 5 layout: use form_label_content block for checkbox and radio labels
  [TwigBridge] Fix compat with Twig v3.9
  [Cache] Sync the Redis proxies with upstream
  [Doctrine Messenger] Fix support for pgsql + pgbouncer.
  [Mailer] Simplify fix
  Do not produce notice/warning when consuming from multiple transports and explicitly listed queues
  [FrameworkBundle] Check if the _route attribute exists on the request
  [Scheduler] fix documentation link
  [PropertyAccess] Fixes getValue() on an unitialized object property on a lazy ghost
  [HttpClient] Make retry strategy work again
  AssetMapper: Remove 'auto-generated' info
  [Mailer] Fix signed emails breaking the profiler
  [Mailer] [Mailgun] Fix expecting payload without tags or user variables
  [Validator] Update Spanish (es) translations
  Fix fetching data in `W3CReferenceTest` on AppVeyor
  Fix SQS visibility_timeout type
  [VarDumper] Fix serialization of stubs with null or uninitialized values

Transport/Connection.php

@@ -510,7 +510,7 @@ public function channel(): \AMQPChannel
     public function queue(string $queueName): \AMQPQueue
     {
         if (!isset($this->amqpQueues[$queueName])) {
-            $queueConfig = $this->queuesOptions[$queueName];
+            $queueConfig = $this->queuesOptions[$queueName] ?? [];
 
             $amqpQueue = $this->amqpFactory->createQueue($this->channel());
             $amqpQueue->setName($queueName);