Merge branch '6.4' into 7.0

* 6.4:
  [AssetMapper] Fixing js sourceMappingURL extraction when sourceMappingURL used in code
  [VarExporter] Deprecate per-property lazy-initializers
  [Routing] Extend old Annotations from new Attributes
  [Mailer] Update default Mailjet port
  Bump Symfony version to 6.4.0
  Update VERSION for 6.4.0-BETA3
  Update CHANGELOG for 6.4.0-BETA3

Author: nicolas-grekas

Annotation/Route.php

@@ -17,7 +17,7 @@ class_exists(\Symfony\Component\Routing\Attribute\Route::class);
 
 if (false) {
     #[\Attribute(\Attribute::IS_REPEATABLE | \Attribute::TARGET_CLASS | \Attribute::TARGET_METHOD)]
-    class Route
+    class Route extends \Symfony\Component\Routing\Attribute\Route
     {
     }
 }

Attribute/Route.php

@@ -14,6 +14,8 @@
 /**
  * @author Fabien Potencier <fabien@symfony.com>
  * @author Alexander M. Turek <me@derrabus.de>
+ *
+ * @final since Symfony 6.4
  */
 #[\Attribute(\Attribute::IS_REPEATABLE | \Attribute::TARGET_CLASS | \Attribute::TARGET_METHOD)]
 class Route