Fix GH-21682: ZipArchive is missing the NOT_SERIALIZABLE flag

ZipArchive allowed serialization, producing a string that unserializes
into an empty object with no open file handle. Add the
@not-serializable annotation so serialize() throws an exception.

Closes GH-21682

Author: iliaal

ext/zip/php_zip.stub.php

@@ -64,6 +64,7 @@ function zip_entry_filesize($zip_entry): int|false {}
 #[\Deprecated(since: '8.0', message: 'use ZipArchive::statIndex() instead')]
 function zip_entry_compressionmethod($zip_entry): string|false {}
 
+/** @not-serializable */
 class ZipArchive implements Countable
 {
     /**

ext/zip/php_zip_arginfo.h

@@ -0,0 +1,16 @@
+--TEST--
+GH-21682 (ZipArchive is missing the NOT_SERIALIZABLE flag)
+--EXTENSIONS--
+zip
+--FILE--
+<?php
+$a = new ZipArchive();
+try {
+    serialize($a);
+    echo "ERROR: should have thrown\n";
+} catch (\Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Serialization of 'ZipArchive' is not allowed