[Contracts] Add mixed type

Signed-off-by: Alexander M. Turek <[email protected]>

Author: derrabus

Deprecation/function.php

@@ -20,7 +20,7 @@
      *
      * @author Nicolas Grekas <[email protected]>
      */
-    function trigger_deprecation(string $package, string $version, string $message, ...$args): void
+    function trigger_deprecation(string $package, string $version, string $message, mixed ...$args): void
     {
         @trigger_error(($package || $version ? "Since $package $version: " : '').($args ? vsprintf($message, $args) : $message), \E_USER_DEPRECATED);
     }