Update utils/readPkgUp.js

Co-authored-by: Jordan Harband <ljharb@gmail.com>

Author: mgwalker

utils/readPkgUp.js

@@ -5,10 +5,7 @@ const fs = require('fs');
 const findUp = require('find-up');
 
 function stripBOM(str) {
-  if(str.charCodeAt(0) === 0xFEFF) {
-    return str.slice(1);
-  }
-  return str;
+  return str.replace(/^\uFEFF/, '');
 }
 
 /**