PHP 8.3 branch cut

Author: ondrejmirtes

.github/workflows/update.yml

@@ -72,7 +72,7 @@ jobs:
         with:
           repository: "php/php-src"
           path: "php-src"
-          ref: "master" # todo 8.3 after feature freeze
+          ref: "PHP-8.3"
       - name: "Update stubs"
         run: "./extractor/extract.php --update -- 8.2 8.3"