Upgrade mysql image version used by Single-Instance Stateful tutorial

fix yml fox version

Author: serut

content/en/docs/tasks/run-application/run-single-instance-stateful-application.md

@@ -76,7 +76,7 @@ for a secure solution.
  Labels: app=mysql
  Containers:
  mysql:
- Image: mysql:5.6
+ Image: mysql:9
  Port: 3306/TCP
  Environment:
  MYSQL_ROOT_PASSWORD: password
@@ -146,7 +146,7 @@ behind a Service and you don't intend to increase the number of Pods.
 Run a MySQL client to connect to the server:
 
 ```shell
-kubectl run -it --rm --image=mysql:5.6 --restart=Never mysql-client -- mysql -h mysql -ppassword
+kubectl run -it --rm --image=mysql:9 --restart=Never mysql-client -- mysql -h mysql -ppassword
 ```
 
 This command creates a new Pod in the cluster running a MySQL client

content/en/examples/application/mysql/mysql-deployment.yaml

@@ -25,7 +25,7 @@ spec:
  app: mysql
  spec:
  containers:
- - image: mysql:5.6
+ - image: mysql:9
  name: mysql
  env:
  # Use secret in real usage