### 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 = read_streams(result)
        snapshot.match("invoke-result", result)
        result_data = result["Payload"]
        result_data = json.loads(result_data)
        assert "application/json" == result["ResponseMetadata"]["HTTPHeaders"]["content-type"]
        assert 200 == result["StatusCode"]
        assert isinstance(result_data, dict)
    @pytest.mark.skip_snapshot_verify(paths=["$..LogResult", "$..ExecutedVersion"])
    def test_invocation_type_event(self, lambda_client, python_function_name, snapshot):
        """Check invocation response for type event"""
        snapshot.add_transformer(snapshot.transform.lambda_api())
        result = lambda_client.invoke(
            FunctionName=python_function_name, Payload=b"{}", InvocationType="Event"
        )
        result = read_streams(result)
        snapshot.match("invoke-result", result)
        assert 202 == result["StatusCode"]
    @pytest.mark.skip_snapshot_verify(paths=["$..LogResult", "$..ExecutedVersion"])
    def test_invocation_type_dry_run(self, lambda_client, python_function_name, snapshot):
        """Check invocation response for type dryrun"""
        snapshot.add_transformer(snapshot.transform.lambda_api())
        result = lambda_client.invoke(
            FunctionName=python_function_name, Payload=b"{}", InvocationType="DryRun"
        )
        result = read_streams(result)
        snapshot.match("invoke-result", result)
        assert 204 == result["StatusCode"]
    @parametrize_python_runtimes
    @pytest.mark.skip_snapshot_verify
    def test_lambda_environment(self, lambda_client, create_lambda_function, runtime, snapshot):