Update dependency phpunit/phpunit to ^12.3.10 (#21)

* Update dependency phpunit/phpunit to ^12.3.10

| datasource | package         | from   | to      |
| ---------- | --------------- | ------ | ------- |
| packagist  | phpunit/phpunit | 12.3.7 | 12.3.10 |

* CS Fix

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Filippo Tessarotto <zoeslam@gmail.com>

Author: renovate[bot]

composer.json

@@ -14,7 +14,7 @@
         "php": "~8.3.0 || ~8.4.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^12.3.7",
+        "phpunit/phpunit": "^12.3.10",
         "slam/php-cs-fixer-extensions": "^3.12.0"
     },
     "autoload": {

lib/r.php

@@ -177,7 +177,7 @@ public static function dump(mixed $var, int $maxDepth = 2, bool $stripTags = tru
             return $dumpText;
         }
 
-        public static function export(mixed $var, int $maxDepth): null|array|bool|float|int|\stdClass|string
+        public static function export(mixed $var, int $maxDepth): array|bool|float|int|\stdClass|string|null
         {
             $isObj  = \is_object($var);