fix: php deprecation warnnig

Author: abdul-kaioum

composer.json

@@ -39,7 +39,7 @@
   },
   "extra": {
     "branch-alias": {
-      "dev-main": "1.x-dev"
+      "dev-main": "2.x-dev"
     }
   },
   "config": {

src/Helpers/Arr.php

@@ -171,7 +171,7 @@ public static function exists($array, $key)
      *
      * @return mixed
      */
-    public static function first($array, callable $callback = null, $default = null)
+    public static function first($array, ?callable $callback = null, $default = null)
     {
         if (\is_null($callback)) {
             if (empty($array)) {
@@ -200,7 +200,7 @@ public static function first($array, callable $callback = null, $default = null)
      *
      * @return mixed
      */
-    public static function last($array, callable $callback = null, $default = null)
+    public static function last($array, ?callable $callback = null, $default = null)
     {
         if (\is_null($callback)) {
             return empty($array) ? self::value($default) : end($array);

src/Http/Request/Request.php

@@ -33,7 +33,7 @@ class Request extends Validator implements ArrayAccess, JsonSerializable
     /**
      * Undocumented function.
      */
-    public function __construct(RouteRegister $route = null)
+    public function __construct(?RouteRegister $route = null)
     {
         $this->route = $route;
         $this->setBody();