DatePicker: not use month parameter on onMonthSelect

[KumJungMin]

Describe the bug

• onMonthSelect() is not use month parameter.

Reproducer

https://stackblitz.com/edit/primevue-create-vue-issue-template?file=README.md

PrimeVue version

4.0.0-beta-2

Vue version

3.x

Language

TypeScript

Build / Runtime

Vue CLI App

Browser(s)

No response

Steps to reproduce the behavior

No response

Expected behavior

No response