Fix cross-version coverage test assertions

Make the coverage regression test assert the restored script output across PHP versions and use a mutable detached XML element for the attribute branch.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: voku

tests/CoverageBoostTest.php

@@ -466,7 +466,7 @@ public function exposeHtml5FallbackForScriptTags(string &$html): void
         $fallbackParser->exposeHtml5FallbackForScriptTags($scriptHtml);
         static::assertSame(
             '<script src="a.js"></script><script>if (a) { document.write("<\/tag>"); }</script>',
-            $scriptHtml
+            HtmlDomParser::putReplacedBackToPreserveHtmlEntities($scriptHtml)
         );
 
         static::assertSame($fallbackParser, $fallbackParser->overwriteSpecialScriptTags(['text/x-custom', 'text/custom']));
@@ -525,9 +525,12 @@ public function callClean(HtmlDomParser $newDocument, bool $removeExtraHeadTag =
         $detachedXmlElement->innertext = '<entry>new</entry>';
         $detachedXmlElement->outertext = '';
         $detachedXmlElement->plaintext = '';
-        $detachedXmlElement->setAttribute('id', 'value');
         static::assertSame('free', $detachedXmlElement->tag);
 
+        $mutableDetachedXmlElement = new SimpleXmlDom((new \DOMDocument())->createElement('free'));
+        $mutableDetachedXmlElement->setAttribute('id', 'value');
+        static::assertSame('value', $mutableDetachedXmlElement->getAttribute('id'));
+
         $xmlFile = \tempnam(\sys_get_temp_dir(), 'simple-xml-dom-xml');
         $htmlFile = \tempnam(\sys_get_temp_dir(), 'simple-xml-dom-html');
         static::assertNotFalse($xmlFile);