### 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_
LOG = logging.getLogger(__name__)
THUNDRA_APIKEY_ENV_VAR_NAME = "THUNDRA_APIKEY"
THUNDRA_AGENT_LAMBDA_HANDLER_ENV_VAR_NAME = "THUNDRA_AGENT_LAMBDA_HANDLER"
THUNDRA_AGENT_LOG_DISABLE_ENV_VAR_NAME = "THUNDRA_AGENT_LAMBDA_LOG_DISABLE"
THUNDRA_APIKEY = os.getenv(THUNDRA_APIKEY_ENV_VAR_NAME)
THUNDRA_JAVA_AGENT_INITIALIZED = False
THUNDRA_JAVA_AGENT_REMOTE_URL: Optional[str] = None
THUNDRA_JAVA_AGENT_LOCAL_PATH: Optional[str] = None
THUNDRA_NODE_AGENT_INITIALIZED = False
THUNDRA_NODE_AGENT_VERSION: Optional[str] = None
THUNDRA_NODE_AGENT_LOCAL_PATH: Optional[str] = None
THUNDRA_NODE_AGENT_LOCAL_PATH_ON_HOST: Optional[str] = None
THUNDRA_PYTHON_AGENT_INITIALIZED = False
THUNDRA_PYTHON_AGENT_VERSION: Optional[str] = None
THUNDRA_PYTHON_AGENT_LOCAL_PATH: Optional[str] = None
THUNDRA_PYTHON_AGENT_LOCAL_PATH_ON_HOST: Optional[str] = None
def _get_apikey(env_vars):
    thundra_apikey = env_vars.get(THUNDRA_APIKEY_ENV_VAR_NAME)
    
    if not thundra_apikey:
        
        thundra_apikey = THUNDRA_APIKEY
    return thundra_apikey
def _ensure_java_agent_initialized():
    global THUNDRA_JAVA_AGENT_INITIALIZED
    if not THUNDRA_JAVA_AGENT_INITIALIZED:
        _init_java_agent_configs()
        _install_java_agent()
        THUNDRA_JAVA_AGENT_INITIALIZED = True
def _get_latest_java_agent_version(metadata_url):