Fix PHP 8.4/8.5 deprecation: "Implicitly marking parameter $default as nullable is deprecated".

Upstream dhii/services has no released fix (newest release is v0.1.1-alpha3, 2023-01-31),
so the explicit nullable type is applied here via composer-patches.

--- a/src/Factories/Alias.php
+++ b/src/Factories/Alias.php
@@ -44,7 +44,7 @@
      *                               given or null, the service will attempt to fetch the original service from the
      *                               container anyway, which will result in a thrown {@link NotFoundExceptionInterface}.
      */
-    public function __construct(string $key, callable $default = null)
+    public function __construct(string $key, ?callable $default = null)
     {
         parent::__construct([]);