test(bezier-react): Improved array test coverage (channel-io#1775)

<!--
  How to write a good PR title:
- Follow [the Conventional Commits
specification](https://www.conventionalcommits.org/en/v1.0.0/).
  - Give as much context as necessary and as little as possible
  - Prefix it with [WIP] while it’s a work in progress
-->

## Self Checklist

- [x] I wrote a PR title in **English** and added an appropriate
**label** to the PR.
- [x] I wrote the commit message in **English** and to follow [**the
Conventional Commits
specification**](https://www.conventionalcommits.org/en/v1.0.0/).
- [ ] I [added the
**changeset**](https://github.com/changesets/changesets/blob/main/docs/adding-a-changeset.md)
about the changes that needed to be released. (or didn't have to)
- [x] I wrote or updated **documentation** related to the changes. (or
didn't have to)
- [x] I wrote or updated **tests** related to the changes. (or didn't
have to)
- [x] I tested the changes in various browsers. (or didn't have to)
  - Windows: Chrome, Edge, (Optional) Firefox
  - macOS: Chrome, Edge, Safari, (Optional) Firefox

## Related Issue
<!-- Please link to issue if one exists -->

<!-- Fixes #0000 -->

## Summary
<!-- Please brief explanation of the changes made -->
- changed isLastIndex -> isArrayLastIndex
- Improved `array` test coverage 

## Details
<!-- Please elaborate description of the changes -->
## TO-BE

![image](https://github.com/channel-io/bezier-react/assets/102217654/83978b0f-7b5a-4e75-bce6-62e777380114)

## AS-IS

![image](https://github.com/channel-io/bezier-react/assets/102217654/966f2837-2367-4887-9d2a-d1f530195376)

### Breaking change? (Yes/No)
<!-- If Yes, please describe the impact and migration path for users -->

## References
<!-- Please list any other resources or points the reviewer should be
aware of -->

packages/bezier-react/src/utils/array.test.ts

@@ -1,20 +1,37 @@
 import {
   compact,
   flattenDeep,
+  isLastIndex,
 } from './array'
 
-describe('arrayUtils', () => {
-  describe('compact', () => {
-    it('should remove falsy item', () => {
-      const array = [0, 1, false, 2, '', 3]
-      expect(compact(array)).toEqual([1, 2, 3])
-    })
+describe('isLastIndex', () => {
+  it('should return true when the last array index', () => {
+    const arr = [0, 1, 2, 3, 4]
+
+    const result = isLastIndex(arr, 4)
+
+    expect(result).toBe(true)
+  })
+
+  it('should return false when not the last array index', () => {
+    const arr = [0, 1, 2, 3, 4]
+
+    const result = isLastIndex(arr, 1)
+
+    expect(result).toBe(false)
   })
+})
+
+describe('compact', () => {
+  it('should remove falsy item', () => {
+    const array = [0, 1, false, 2, '', 3]
+    expect(compact(array)).toEqual([1, 2, 3])
+  })
+})
 
-  describe('flattenDeep', () => {
-    it('should return flatten array', () => {
-      const array = [1, [2, [3, [4]], 5]]
-      expect(flattenDeep(array)).toEqual([1, 2, 3, 4, 5])
-    })
+describe('flattenDeep', () => {
+  it('should return flatten array', () => {
+    const array = [1, [2, [3, [4]], 5]]
+    expect(flattenDeep(array)).toEqual([1, 2, 3, 4, 5])
   })
 })

packages/bezier-react/src/utils/array.ts

@@ -1,6 +1,6 @@
 import { isArray } from './type'
 
-export function isLastIndex(array: any[], index: number) {
+export function isLastIndex(array: ArrayLike<unknown>, index: number) {
   return array.length - 1 === index
 }