[ecs] AlarmNames should be optional

[axot]

Describe the bug
When updating service.ecs.services.k8s.aws, the controller shows the following error

"error": "InvalidParameter: 1 validation error(s) found.\n- missing required field, UpdateServiceInput.DeploymentConfiguration.Alarms.AlarmNames.\n",

Steps to reproduce

1. import exists ecs service
2. edit service's desiredCount

an example AdoptedResource

apiVersion: services.k8s.aws/v1alpha1
kind: AdoptedResource
metadata:
  name: hello
  namespace: hello
spec:
  aws:
    nameOrID: hello
    additionalKeys:
      cluster: cluster-hello
  kubernetes:
    group: ecs.services.k8s.aws
    kind: Service

Expected outcome
No error when applying service

Environment
EKS

• Kubernetes version 1.29
• Using EKS (yes/no), if so version? yes, 1.29
• AWS service targeted (S3, RDS, etc.) ecs