Fix explicit nullable parameter for PHP 8.4 compatibility (#233)

Author: GromNaN

.php-cs-fixer.dist.php

@@ -40,5 +40,6 @@
             'keep_multiple_spaces_after_comma' => true,
         ],
         'single_trait_insert_per_statement' => true,
+        'nullable_type_declaration_for_default_null_value' => true,
     ])
     ->setRiskyAllowed(true);

composer.json

@@ -38,6 +38,11 @@
     "scripts": {
         "test": "vendor/bin/pest"
     },
+    "extra": {
+        "branch-alias": {
+            "dev-main": "3.x-dev"
+        }
+    },
     "config": {
         "allow-plugins": {
             "pestphp/pest-plugin": true

src/ArrayToXml.php

@@ -68,10 +68,10 @@ public static function convert(
         array $array,
         $rootElement = '',
         bool $replaceSpacesByUnderScoresInKeyNames = true,
-        string $xmlEncoding = null,
+        ?string $xmlEncoding = null,
         string $xmlVersion = '1.0',
         array $domProperties = [],
-        bool $xmlStandalone = null,
+        ?bool $xmlStandalone = null,
         bool $addXmlDeclaration = true,
         array $options = ['convertNullToXsiNil' => false]
     ): string {