came to the same issue when trying to deploy a sample app in a documentation example. But I found that AWS ECS CLI has support for compose files deployment, maybe that's why docker retired their integration? I don't know, but leaving the answer here anyways. Maybe it still helps you or anybody else who step into this :)

https://github.com/aws/amazon-ecs-cli

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/copilot-deploy.html