remove "useless" escape (#1436)

closes symfony/symfony#60983

Author: craigh

symfony/stimulus-bundle/2.20/assets/controllers/csrf_protection_controller.js

@@ -1,5 +1,5 @@
 const nameCheck = /^[-_a-zA-Z0-9]{4,22}$/;
-const tokenCheck = /^[-_\/+a-zA-Z0-9]{24,}$/;
+const tokenCheck = /^[-_/+a-zA-Z0-9]{24,}$/;
 
 // Generate and double-submit a CSRF token in a form field and a cookie, as defined by Symfony's SameOriginCsrfTokenManager
 document.addEventListener('submit', function (event) {