### 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_
result = sqs_client.receive_message(QueueUrl=queue_url, MessageAttributeNames=["All"])
            assert len(result["Messages"]) > 0
            msg_attrs = result["Messages"][0]["MessageAttributes"]
            assert "RequestID" in msg_attrs
            assert "ErrorCode" in msg_attrs
            assert "ErrorMessage" in msg_attrs
            snapshot.match("sqs_dlq_message", result)
        
        retry(receive_dlq, retries=120, sleep=3)
        
        update_function_config_response = lambda_client.update_function_configuration(
            FunctionName=lambda_name, DeadLetterConfig={}
        )
        snapshot.match("delete_dlq", update_function_config_response)
        
        result = lambda_client.invoke(
            FunctionName=lambda_name, Payload=json.dumps(payload), LogType="Tail"
        )
        result = read_streams(result)
        payload = json.loads(to_str(result["Payload"]))
        snapshot.match("result_payload", payload)
        assert 200 == result["StatusCode"]
        assert "Unhandled" == result["FunctionError"]
        assert "$LATEST" == result["ExecutedVersion"]