Drop erroneous CLEAN section

It doesn't belong to this test case, and may actually interfere with
HTMLDocument_Windows1251.phpt[1].

[1] <https://github.com/php/php-src/actions/runs/10434868303/job/28898227793>

ext/dom/tests/modern/html/encoding/HTMLDocument_fallback_encoding.phpt

@@ -9,10 +9,6 @@ $dom = Dom\HTMLDocument::createFromFile(__DIR__ . "/fallback_encoding.html");
 var_dump($dom->inputEncoding);
 echo $dom->saveHtml();
 
-?>
---CLEAN--
-<?php
-@unlink(__DIR__ . "/windows1251_output.tmp");
 ?>
 --EXPECT--
 string(5) "UTF-8"