Bump Symfony version to 5.4.15

Author: fabpot

Kernel.php

@@ -78,12 +78,12 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
      */
     private static $freshCache = [];
 
-    public const VERSION = '5.4.14';
-    public const VERSION_ID = 50414;
+    public const VERSION = '5.4.15-DEV';
+    public const VERSION_ID = 50415;
     public const MAJOR_VERSION = 5;
     public const MINOR_VERSION = 4;
-    public const RELEASE_VERSION = 14;
-    public const EXTRA_VERSION = '';
+    public const RELEASE_VERSION = 15;
+    public const EXTRA_VERSION = 'DEV';
 
     public const END_OF_MAINTENANCE = '11/2024';
     public const END_OF_LIFE = '11/2025';