avoid array_find_key (#38)

Author: rodrigopedra

src/helpers.php

@@ -98,9 +98,13 @@ function array_first($array, ?callable $callback = null, $default = null)
             return value($default);
         }
 
-        $key = array_find_key($array, $callback);
+        foreach ($array as $key => $value) {
+            if ($callback($value, $key)) {
+                return $value;
+            }
+        }
 
-        return $key !== null ? $array[$key] : value($default);
+        return value($default);
     }
 }