fix(curriculum): improve test robustness (#39004)

* Add: // Only change code...comments

* Allow user to modify bob

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/make-a-person.english.md

@@ -70,6 +70,7 @@ tests:
 
 ```js
 var Person = function(firstAndLast) {
+  // Only change code below this line
   // Complete the method below and implement the others similarly
   this.getFullName = function() {
     return "";
@@ -83,6 +84,17 @@ bob.getFullName();
 
 </div>
 
+### After Test
+
+<div id='js-teardown'>
+
+```js
+if(bob){
+  bob = new Person("Bob Ross");
+}
+```
+
+</div>
 
 
 </section>