[SPARK-52028] Update README.md with YuniKorn 1.6.3

Author: dongjoon-hyun

README.md

@@ -93,7 +93,7 @@ $ helm repo add yunikorn https://apache.github.io/yunikorn-release
 
 $ helm repo update
 
-$ helm install yunikorn yunikorn/yunikorn --namespace yunikorn --version 1.6.2 --create-namespace --set embedAdmissionController=false
+$ helm install yunikorn yunikorn/yunikorn --namespace yunikorn --version 1.6.3 --create-namespace --set embedAdmissionController=false
 ```
 
 Submit a Spark app to YuniKorn enabled cluster: