fix(curriculum) replace head content regex (freeCodeCamp#55923)

Author: lasjorg

curriculum/challenges/english/14-responsive-web-design-22/learn-html-forms-by-building-a-registration-form/62cc5b1779e4d313466f73c5.md

@@ -39,7 +39,7 @@ assert.notMatch(code, /<\/link>/);
 Your `link` element should be inside your `head` element.
 
 ```js
-const headContentRegex = /(?<=<head\s*>)(?:.|\s*)*?(?=<\/head\s*>)/;
+const headContentRegex = /(?<=<head\s*>)[\S|\s]*(?=<\/head\s*>)/;
 const headElementContent = code.match(headContentRegex);
 
 const headElement = document.createElement("head");