Update Readme badge with Kubernetes 1.24 version

Signed-off-by: Xabier Larrakoetxea <me@slok.dev>

Readme.md

@@ -9,7 +9,7 @@
 [![GoDoc](https://godoc.org/github.com/slok/kubewebhook/v2?status.svg)][godoc-url]
 [![Apache 2 licensed](https://img.shields.io/badge/license-Apache2-blue.svg)](https://raw.githubusercontent.com/slok/kubewebhook/master/LICENSE)
 [![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/slok/kubewebhook)](https://github.com/slok/kubewebhook/releases/latest)
-![Kubernetes release](https://img.shields.io/badge/Kubernetes-v1.23-green?logo=Kubernetes&style=flat&color=326CE5&logoColor=white)
+![Kubernetes release](https://img.shields.io/badge/Kubernetes-v1.24-green?logo=Kubernetes&style=flat&color=326CE5&logoColor=white)
 
 Kubewebhook is a small Go framework to create [external admission webhooks][aw-url] for Kubernetes.