Replace hack with `track_latest` attribute

[bryantbiggs]

Is your request related to a new offering from AWS?

Is this functionality available in the AWS provider for Terraform? See CHANGELOG.md, too.

• No 🛑: please wait to file a request until the functionality is avaialble in the AWS provider
• Yes ✅: please list the AWS provider version which introduced this functionality

Is your request related to a problem? Please describe.

• This ugly hack https://github.com/terraform-aws-modules/terraform-aws-ecs/blob/8b97783def49997d18a6fcb00dc21ce1edc0f538/modules/service/main.tf#L589-L608

Describe the solution you'd like.

• https://github.com/hashicorp/terraform-provider-aws/pull/30154

Describe alternatives you've considered.

Additional context