[5.4] Remove the callable type hint for array_sort. (#19483)

* Remove the type hint callable for `array_sort`

As `Arr::sort()` can accept a string, we should not force a callable here, and have to accept a string (with dot notation) too!

* Update helpers.php

src/Illuminate/Support/helpers.php

@@ -264,13 +264,13 @@ function array_set(&$array, $key, $value)
 
 if (! function_exists('array_sort')) {
     /**
-     * Sort the array using the given callback.
+     * Sort the array by the given callback or attribute name.
      *
      * @param  array  $array
-     * @param  callable  $callback
+     * @param  callable|string  $callback
      * @return array
      */
-    function array_sort($array, callable $callback)
+    function array_sort($array, $callback)
     {
         return Arr::sort($array, $callback);
     }