challenges: description improvement (#39197)

Co-authored-by: PeterF521 <peterf521@gmail.com>

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice.english.md

@@ -10,7 +10,7 @@ forumTopicId: 301148
 ## Description
 <section id='description'>
 You are given two arrays and an index.
-Use the array methods <code>slice</code> and <code>splice</code> to copy each element of the first array into the second array, in order.
+Copy each element of the first array into the second array, in order.
 Begin inserting elements at index <code>n</code> of the second array.
 Return the resulting array. The input arrays should remain the same after the function runs.
 </section>