[DeepClone] Add XMLWriter, XMLReader, SNMP, tidy, tidyNode to NOT_ROUND_TRIPPABLE

These classes wrap native C handles and silently lose state through
property restoration. Matches php/php-src#21694 which adds
NOT_SERIALIZABLE to them; the explicit list protects older PHP
versions where the flag isn't set yet.

Author: nicolas-grekas

src/DeepClone/DeepClone.php

@@ -35,7 +35,12 @@ final class DeepClone
      * losing the underlying file handle / connection / archive / etc.
      */
     private const NOT_ROUND_TRIPPABLE = [
-        \ZipArchive::class => true,
+        'ZipArchive' => true,
+        'XMLWriter' => true,
+        'XMLReader' => true,
+        'SNMP' => true,
+        'tidy' => true,
+        'tidyNode' => true,
     ];
 
     private static array $reflectors = [];