### 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_
"""
        Determine the network of a docker container.
        :param func_arn: The ARN of the lambda function.
        :return: name of the container network
        """
        with self.docker_container_lock:
            status = self.get_docker_container_status(func_arn)
            
            if status == 0:
                return ""
            
            container_name = self.get_container_name(func_arn)
            container_network = DOCKER_CLIENT.get_networks(container_name)[0]
            return container_network
    def idle_container_destroyer(self):
        """
        Iterates though all the lambda containers and destroys any container that has
        been inactive for longer than MAX_CONTAINER_IDLE_TIME_MS.
        :return: None
        """
        LOG.debug("Checking if there are idle containers ...")
        current_time = int(time.time() * 1000)
        for func_arn, last_run_time in dict(self.function_invoke_times).items():
            duration = current_time - last_run_time
            
            if duration < MAX_CONTAINER_IDLE_TIME_MS:
                continue
            
            self.destroy_docker_container(func_arn)
    def start_idle_container_destroyer_interval(self):