[ENG-11520](https://linear.app/comm/issue/ENG-11520/terraform-error-with-aws-ami).
The issue was that the AMI query was looking for a specific version (amzn2-ami-ecs-hvm-2.0.20231024-x86_64-ebs) that no longer exists. I changed it to use a wildcard
pattern (amzn2-ami-ecs-hvm-*-x86_64-ebs) which will match the most recent ECS-optimized Amazon Linux 2 AMI.
Additionally, we're going to shut it down in a couple of days anyway, so I added `ignore_changes` to the launch template. This will prevent Terraform from updating the ECS instances when the AMI changes - there is no point in that.
Without this diff, Terraform deployments are blocked.
Depends on D15519