Merge branch '6.4' into 7.0

* 6.4: (47 commits)
  Sync .github/expected-missing-return-types.diff
  [FrameworkBundle] Add void return-type to ErrorLoggerCompilerPass
  [DoctrineBridge] Fix cross-versions compat
  [HttpKernel] Handle nullable callback of StreamedResponse
  [Mailer] Capitalize sender header for Mailgun
  [FrameworkBundle] Configure `logger` as error logger if the Monolog Bundle is not registered
  DX: PHP CS Fixer - drop explicit nullable_type_declaration_for_default_null_value config, as it's part of ruleset anyway
  DX: PHP CS Fixer - drop explicit no_superfluous_phpdoc_tags config, as it's part of ruleset already
  [DI] Simplify using DI attributes with `ServiceLocator/Iterator`'s
  [FrameworkBundle] Fix registering workflow.registry
  Revert "Add keyword `dev` to leverage composer hint"
  [Validator] Add missing Ukrainian translations #51960
  [Validator] Add missing translations for Indonesian (id)
  [Validator] Add missing translations for Vietnamese (VI)
  Add missing Validator translations - Croatian (hr)
  [HttpFoundation]  Improve PHPDoc of Cache attribute
  [Validator] Add missing Spanish (es) translations #51956
  [Serializer] Add `XmlEncoder::CDATA_WRAPPING` context option
  [Finder] Add early directory prunning filter support
  Add missing dutch translations
  ...

Author: nicolas-grekas

Request.php

@@ -158,7 +158,8 @@ class Request
 
     protected static ?\Closure $requestFactory = null;
 
-    private string $preferredFormat;
+    private ?string $preferredFormat = null;
+
     private bool $isHostValid = true;
     private bool $isForwardedValid = true;
     private bool $isSafeContentPreferred;

StreamedResponse.php

@@ -57,8 +57,12 @@ public function setCallback(callable $callback): static
         return $this;
     }
 
-    public function getCallback(): \Closure
+    public function getCallback(): ?\Closure
     {
+        if (!isset($this->callback)) {
+            return null;
+        }
+
         return ($this->callback)(...);
     }