Merge branch '6.4' into 7.0

* 6.4:
  stop marking parameters implicitly as nullable
  include message id provided by the MTA when dispatching the SentMessageEvent

Author: xabbuh

Tests/Fixtures/includes/autowiring_classes.php

@@ -16,7 +16,7 @@ class Foo
     public static int $counter = 0;
 
     #[Required]
-    public function cloneFoo(\stdClass $bar = null): static
+    public function cloneFoo(?\stdClass $bar = null): static
     {
         ++self::$counter;
 

Tests/Fixtures/includes/autowiring_classes_80.php

@@ -107,7 +107,7 @@ public function __construct(string $arg1, #[AutowireDecorated] AsDecoratorInterf
 #[AsDecorator(decorates: \NonExistent::class, onInvalid: ContainerInterface::NULL_ON_INVALID_REFERENCE)]
 class AsDecoratorBaz implements AsDecoratorInterface
 {
-    public function __construct(#[AutowireDecorated] AsDecoratorInterface $inner = null)
+    public function __construct(#[AutowireDecorated] ?AsDecoratorInterface $inner = null)
     {
     }
 }

Tests/Fixtures/includes/classes.php

@@ -83,7 +83,7 @@ public function callPassed()
 
 class DummyProxyDumper implements DumperInterface
 {
-    public function isProxyCandidate(Definition $definition, bool &$asGhostObject = null, string $id = null): bool
+    public function isProxyCandidate(Definition $definition, ?bool &$asGhostObject = null, ?string $id = null): bool
     {
         $asGhostObject = false;