### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

The use case I have in mind is to run Node 16.x Lambdas - the default container registry is `lambci/lambda` which is effectively abandoned. [Not even Node 14.x has been published](https://github.com/lambci/docker-lambda/pull/330). However, switching the registry over to [`amazon/aws-lambda-nodejs`](https://hub.docker.com/r/amazon/aws-lambda-nodejs) still fails to pull the container, since localstack is looking for the tag `nodejs16.x`. I'd like to be able to specify that if the runtime is `nodejs16.x` it just looks for tag `16`.

### 🧑‍💻 Implementation

_No response_

### Anything else?

_No response_
container_config.env_vars["DOCKER_LAMBDA_API_PORT"] = port
            container_config.env_vars["DOCKER_LAMBDA_RUNTIME_PORT"] = port
        container_config.additional_flags = inv_context.docker_flags or ""
        container_config.dns = config.LAMBDA_DOCKER_DNS
        container_config.ports = PortMappings()
        if Util.debug_java_port:
            container_config.ports.add(Util.debug_java_port)
        container_config.command = inv_context.lambda_command
        container_config.remove = True
        container_config.interactive = True
        container_config.detach = background
        lambda_cwd = lambda_function.cwd
        if lambda_cwd:
            if config.LAMBDA_REMOTE_DOCKER:
                container_config.required_files.append((f"{lambda_cwd}/.", DOCKER_TASK_FOLDER))
            else:
                container_config.required_files.append(
                    (Util.get_host_path_for_path_in_docker(lambda_cwd), DOCKER_TASK_FOLDER)
                )
        
        on_docker_separate_execution.run(lambda_function, container_config)
        
        
        if not config.LAMBDA_REMOTE_DOCKER and container_config.required_files:
            container_config.volumes = container_config.volumes or []
            container_config.volumes += container_config.required_files
        container_id = DOCKER_CLIENT.create_container(
            image_name=container_config.image_name,
            interactive=container_config.interactive,
            entrypoint=container_config.entrypoint,