### 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_
try:
        from distutils.version import StrictVersion
        import requests
        response = requests.get("https://pypi.org/pypi/thundra/json")
        data = json.loads(response.content.decode())
        versions = sorted(list(data["releases"].keys()), key=StrictVersion, reverse=True)
        return versions[0]
    except Exception as e:
        print("Unable to get latest version of Thundra Python agent: %s" % e)
        return None
def _init_python_agent_configs() -> bool:
    global THUNDRA_PYTHON_AGENT_VERSION
    global THUNDRA_PYTHON_AGENT_LOCAL_PATH
    global THUNDRA_PYTHON_AGENT_LOCAL_PATH_ON_HOST
    latest_version = _get_latest_python_agent_version()
    version = os.getenv("THUNDRA_AGENT_PYTHON_VERSION", latest_version)
    if not version:
        return False
    THUNDRA_PYTHON_AGENT_VERSION = version.strip()
    THUNDRA_PYTHON_AGENT_LOCAL_PATH = "%s/thundra/python/%s/" % (
        config.dirs.tmp,
        THUNDRA_PYTHON_AGENT_VERSION,
    )
    THUNDRA_PYTHON_AGENT_LOCAL_PATH_ON_HOST = "%s/thundra/python/%s/" % (
        config.dirs.functions,
        THUNDRA_PYTHON_AGENT_VERSION,
    )
    return True
def _install_python_agent() -> bool: