Fix issue when providing an array with numeric index for client hint factory (#7265)

* Fix issue when providing an array with numeric index for client hint factory
* Update ClientHints.php

Author: sgiehl

ClientHints.php

@@ -236,7 +236,7 @@ public static function factory(array $headers): ClientHints
         $fullVersionList = [];
 
         foreach ($headers as $name => $value) {
-            switch (\str_replace('_', '-', \strtolower($name))) {
+            switch (\str_replace('_', '-', \strtolower((string) $name))) {
                 case 'http-sec-ch-ua-arch':
                 case 'sec-ch-ua-arch':
                 case 'arch':