### 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:
                        result = self._execute(lambda_function, inv_context)
                    except Exception as e:
                        raised_error = e
                        dlq_sent = handle_error(lambda_function, event, e, asynchronous)
                        raise e
                    finally:
                        self.function_invoke_times[func_arn] = invocation_time
                        callback and callback(
                            result, func_arn, event, error=raised_error, dlq_sent=dlq_sent
                        )
                        lambda_result_to_destination(
                            lambda_function, event, result, asynchronous, raised_error
                        )
                    
                    return result
            return _run(func_arn=func_arn)
        
        if asynchronous:
            LOG.debug(
                "Lambda executed in Event (asynchronous) mode, no response will be returned to caller"
            )
            FuncThread(do_execute).start()
            return InvocationResult(None, log_output="Lambda executed asynchronously.")
        return do_execute()
    def _execute(self, lambda_function: LambdaFunction, inv_context: InvocationContext):
        """This method must be overwritten by subclasses."""
        raise NotImplementedError
    def startup(self):