Update Kotlin Version In Readme.md (#3525)

Update Kotlin Version In Readme.md

README.md

@@ -3,7 +3,7 @@
 A V2Ray client for Android, support [Xray core](https://github.com/XTLS/Xray-core) and [v2fly core](https://github.com/v2fly/v2ray-core)
 
 [![API](https://img.shields.io/badge/API-21%2B-yellow.svg?style=flat)](https://developer.android.com/about/versions/lollipop)
-[![Kotlin Version](https://img.shields.io/badge/Kotlin-1.6.21-blue.svg)](https://kotlinlang.org)
+[![Kotlin Version](https://img.shields.io/badge/Kotlin-1.9.23-blue.svg)](https://kotlinlang.org)
 [![GitHub commit activity](https://img.shields.io/github/commit-activity/m/2dust/v2rayNG)](https://github.com/2dust/v2rayNG/commits/master)
 [![CodeFactor](https://www.codefactor.io/repository/github/2dust/v2rayng/badge)](https://www.codefactor.io/repository/github/2dust/v2rayng)
 [![GitHub Releases](https://img.shields.io/github/downloads/2dust/v2rayNG/latest/total?logo=github)](https://github.com/2dust/v2rayNG/releases)