Remove useless u flags in regular expressions (#18509)

tests/integration/plugins/languages/is-supported.js

@@ -14,7 +14,7 @@ const languages = [
         throw new Error("Unexpected non absolute path");
       }
 
-      return /(?<separator>[\\/])\.husky\k<separator>[^\\/]+$/u.test(filepath);
+      return /(?<separator>[\\/])\.husky\k<separator>[^\\/]+$/.test(filepath);
     },
   },
 ];