Bump EKS version

Author: rapgaws

PetAdoptions/cdk/pet_stack/lib/services.ts

@@ -344,7 +344,7 @@ export class Services extends Stack {
             defaultCapacity: 2,
             defaultCapacityInstance: ec2.InstanceType.of(ec2.InstanceClass.T3, ec2.InstanceSize.MEDIUM),
             secretsEncryptionKey: secretsKey,
-            version: KubernetesVersion.of('1.28'),
+            version: KubernetesVersion.of('1.31'),
             kubectlLayer: new KubectlLayer(this, 'kubectl'),
             authenticationMode: eks.AuthenticationMode.API_AND_CONFIG_MAP,
         });