### Is there an existing issue for this?

- [X] I have searched the existing issues and read the documentation

### Question

A [recent commit](https://github.com/localstack/localstack/commit/f41b25cc8d68e97ce8eacd4374ded4a8072e50f6#diff-368e25a43c4a3200ecb9ae21e7b2a94da05d8eb24680bd6c2a37ee0e275bcd0aL67) scrapped the `{"features:initScripts":"initialized"}` feature that my team was relying on to bootstrap our development environment.

Basically we are putting a provisioning script in `/docker-entrypoint-initaws.d/` that installs Terraform and runs our Terraform definitions against `http://localhost:4566`. Then, the service that needs the AWS infrastructure has an entrypoint that polls `http://localstack:4566/health` and keeps looking for `{"features:initScripts":"initialized"}` in the response before attempting to actually start the service.

We found by trial and error that this was the most reliable way to bring up our stack, as opposed to looking for specific services to appear in the `/health` payload. However, now with this change we can't detect exactly when our Terraform provisioning finishes. It'd be great to get back that feature, or to have another way to detect when the LocalStack entrypoint has finished running the scripts in `/docker-entrypoint-initaws.d/`. For now we'll be sticking to `:0.12.19` instead of `:latest` as suggested.

Thank you.

### Anything else?

_No response_
return "cloudwatch", config.PORT_CLOUDWATCH
    
    if _in_path_or_payload("QueueUrl=") and _in_path_or_payload("Action="):
        return "sqs", config.PORT_SQS
    if matches_service_action("sqs", action, version=version):
        return "sqs", config.PORT_SQS
    
    if matches_service_action("sns", action, version=version):
        return "sns", config.PORT_SNS
    
    stripped = path.strip("/")
    if method in ["GET", "HEAD"] and "/" in stripped:
        
        return "s3", config.PORT_S3
    
    if stripped and "/" not in stripped:
        if method == "HEAD":
            
            return "s3", config.PORT_S3
        if method == "PUT":
            
            return "s3", config.PORT_S3
        if method == "POST" and is_s3_form_data(data_bytes):
            
            return "s3", config.PORT_S3
    
    if "aws-cli/" in headers.get("User-Agent", ""):
        return "s3", config.PORT_S3
    
    if (