fix style hash

Author: schultek

site/lib/src/layouts/dash_layout.dart

@@ -102,9 +102,7 @@ abstract class FlutterDocsLayout extends PageLayoutBase {
       ),
       link(
         rel: 'stylesheet',
-        href:
-            '/assets/css/main.css?'
-            'hash=${htmlEscape.convert(generatedStylesHash)}',
+        href: '/assets/css/main.css?hash=$generatedStylesHash',
       ),
 
       if (pageData['js'] case final List<Object?> jsList)