### 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_
logs_client,
        snapshot,
    ):
        """tests the local context reuse of packages in AWS lambda"""
        snapshot.add_transformer(snapshot.transform.lambda_api())
        func_name = f"test_lambda_{short_uid()}"
        create_result = create_lambda_function(
            func_name=func_name,
            handler_file=lambda_fn,
            runtime=lambda_runtime,
            client=lambda_client,
            timeout=1,
        )
        snapshot.match("create-result", create_result)
        result = lambda_client.invoke(FunctionName=func_name, Payload=json.dumps({"wait": 2}))
        snapshot.match("invoke-result", result)
        assert result["StatusCode"] == 200
        log_group_name = f"/aws/lambda/{func_name}"
        ls_result = logs_client.describe_log_streams(logGroupName=log_group_name)
        log_stream_name = ls_result["logStreams"][0]["logStreamName"]
        def assert_events():
            log_events = logs_client.get_log_events(
                logGroupName=log_group_name, logStreamName=log_stream_name
            )["events"]
            assert any(["starting wait" in e["message"] for e in log_events])
            assert not any(["done waiting" in e["message"] for e in log_events])
        retry(assert_events, retries=15)
    @pytest.mark.parametrize(
        ["lambda_fn", "lambda_runtime"],
        [