Improve comment on return parameter

src/MD_STD_IN.php

@@ -113,7 +113,7 @@ public static function sanitize_rgb_color(mixed $input):string {
      *
      * @param array<mixed> $inputs Input array.
      *
-     * @return array<integer>
+     * @return list<integer>
      */
     public static function sanitize_id_array(array $inputs):array {