fix a test name

Author: zloirock

tests/unit-global/es.typed-array.at.js

@@ -1,6 +1,6 @@
 import { DESCRIPTORS, TYPED_ARRAYS } from '../helpers/constants.js';
 
-if (DESCRIPTORS) QUnit.test('%TypedArrayPrototype%.indexOf', assert => {
+if (DESCRIPTORS) QUnit.test('%TypedArrayPrototype%.at', assert => {
   // we can't implement %TypedArrayPrototype% in all engines, so run all tests for each typed array constructor
   for (const { name, TypedArray } of TYPED_ARRAYS) {
     const { at } = TypedArray.prototype;