### 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_
def __init__(self, msg, code=400):
        super(ClientError, self).__init__(msg)
        self.code = code
        self.msg = msg
    def get_response(self):
        if isinstance(self.msg, Response):
            return self.msg
        return error_response(self.msg, self.code)
@lru_cache()
def get_default_executor_mode() -> str:
    """
    Returns the default docker executor mode, which is "docker" if the docker socket is available via the docker
    client, or "local"  otherwise.
    :return:
    """
    try:
        return "docker" if DOCKER_CLIENT.has_docker() else "local"
    except Exception:
        return "local"
def get_executor_mode() -> str:
    """
    Returns the currently active lambda executor mode. If config.LAMBDA_EXECUTOR is set, then it returns that,
    otherwise it falls back to get_default_executor_mode().
    :return: the lambda executor mode (e.g., 'local', 'docker', or 'docker-reuse')
    """
    return config.LAMBDA_EXECUTOR or get_default_executor_mode()
def multi_value_dict_for_list(elements: Union[List, Dict]) -> Dict: