### 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_
required_files: List[Tuple[str, str]] = dataclasses.field(default_factory=list)
class LambdaExecutorContainers(LambdaExecutor):
    """Abstract executor class for executing Lambda functions in Docker containers"""
    def execute_in_container(
        self,
        lambda_function: LambdaFunction,
        inv_context: InvocationContext,
        stdin=None,
        background=False,
    ) -> Tuple[bytes, bytes]:
        raise NotImplementedError
    def run_lambda_executor(self, lambda_function: LambdaFunction, inv_context: InvocationContext):
        env_vars = inv_context.environment
        runtime = lambda_function.runtime or ""
        event = inv_context.event
        stdin_str = None
        event_body = event if event is not None else env_vars.get("AWS_LAMBDA_EVENT_BODY")
        event_body = json.dumps(event_body) if isinstance(event_body, dict) else event_body
        event_body = event_body or ""
        is_large_event = len(event_body) > MAX_ENV_ARGS_LENGTH
        is_provided = runtime.startswith(LAMBDA_RUNTIME_PROVIDED)
        if (
            not is_large_event
            and lambda_function
            and is_provided