### 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_
self.destroy_docker_container(func_arn)
                
                LOG.debug("Creating container: %s", container_name)
                self.create_container(lambda_function, env_vars, lambda_cwd, docker_flags)
                LOG.debug("Starting docker-reuse Lambda container: %s", container_name)
                DOCKER_CLIENT.start_container(container_name)
                def wait_up():
                    cont_status = DOCKER_CLIENT.get_container_status(container_name)
                    assert cont_status == DockerContainerStatus.UP
                    if not in_docker():
                        return
                    
                    lambda_docker_ip = DOCKER_CLIENT.get_container_ip(container_name)
                    if self._should_use_stay_open_mode(lambda_function, lambda_docker_ip):
                        full_url = self._get_lambda_stay_open_url(lambda_docker_ip)
                        wait_for_port_open(full_url, sleep_time=0.5, retries=8)
                
                retry(wait_up, retries=15, sleep=0.8)
            container_network = self.get_docker_container_network(func_arn)
            entry_point = DOCKER_CLIENT.get_image_entrypoint(docker_image)
            LOG.debug(
                'Using entrypoint "%s" for container "%s" on network "%s".',
                entry_point,
                container_name,
                container_network,
            )
            return ContainerInfo(container_name, entry_point)
    def create_container(
        self,