How does one use Docker DIND and AWS CLI together as a service

Question

I use Gitlab CI to deploy to AWS ECS. As such, I need two things from the Gitlab environment:

• Docker-in-Docker - so I can run docker build etc
• AWS CLI - to deploy to ECS with the AWS CLI

This is a snippet of my stage in Gitlab CI. Although the AWS CLI bit doesn't make sense, it is enough to demonstrate the problem I am facing:

dockerise-dev:
  stage: build
  image: docker:20.10.12
  services:
    - name: docker:20.10.12-dind
    - name: amazon/aws-cli:2.15.26
      entrypoint: [""]
  script:
    - docker build .
    - aws s3 ls

But I get the error below:

ERROR: Preparation failed: Error response from daemon: no command specified (docker.go:436:0s)

How do i make use of the amazon/aws-cli:2.15.26 as a service so I don't have to install aws cli separately?

Thanks