Merge branch '6.3' into 6.4

* 6.3:
  [6.3] Remove unused test fixture
  [5.4] Remove unused test fixtures
  [Dotent] Add PHPDoc for `$overrideExistingVars`
  [SecurityBundle] Fix missing login-link element in xsd schema
  [Validator] Add missing Chinese translations #51934
  [Serializer] Fix using `DateIntervalNormalizer` with union types
  [Validator] fix: add missing translations for for Thai (th)
  fix #52273 [doctrine-messenger] DB table locks on messenger_messages with many failures
  [Serializer] Handle defaultContext for DateTimeNormalizer
  declare constructor argument as optional for backwards compatibility
  [CI] Add step to verify symfony/deprecation-contracts requirements

Exception/DelayedMessageHandlingException.php

@@ -23,9 +23,10 @@ class DelayedMessageHandlingException extends RuntimeException implements Wrappe
 {
     use WrappedExceptionsTrait;
 
-    private Envelope $envelope;
+    private array $exceptions;
+    private ?Envelope $envelope;
 
-    public function __construct(array $exceptions, Envelope $envelope)
+    public function __construct(array $exceptions, Envelope $envelope = null)
     {
         $this->envelope = $envelope;
 
@@ -55,7 +56,7 @@ public function getExceptions(): array
         return $this->exceptions;
     }
 
-    public function getEnvelope(): Envelope
+    public function getEnvelope(): ?Envelope
     {
         return $this->envelope;
     }

Worker.php

@@ -189,7 +189,7 @@ private function ack(): bool
                     $receiver->reject($envelope);
                 }
 
-                if ($e instanceof HandlerFailedException || $e instanceof DelayedMessageHandlingException) {
+                if ($e instanceof HandlerFailedException || ($e instanceof DelayedMessageHandlingException && null !== $e->getEnvelope())) {
                     $envelope = $e->getEnvelope();
                 }