### 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_
handler="handler",
            runtime=LAMBDA_RUNTIME_GOLANG,
        )
        snapshot.match("create-result", create_result)
        
        result = lambda_client.invoke(
            FunctionName=func_name, Payload=json.dumps({"name": "pytest"})
        )
        result = read_streams(result)
        snapshot.match("invoke-result", result)
        result_data = result["Payload"]
        assert result["StatusCode"] == 200
        assert result_data.strip() == '"Hello pytest!"'
parametrize_java_runtimes = pytest.mark.parametrize(
    "runtime",
    JAVA_TEST_RUNTIMES,
)
class TestJavaRuntimes:
    @pytest.fixture(scope="class")
    def test_java_jar(self) -> bytes:
        
        java_file = load_file(TEST_LAMBDA_JAVA, mode="rb")
        if not java_file:
            raise Exception(
                f"Test dependency {TEST_LAMBDA_JAVA} not found."
                "Please make sure to run 'make init-testlibs' to ensure the file is available."
            )
        return java_file
    @pytest.fixture(scope="class")
    def test_java_zip(self, tmpdir_factory, test_java_jar) -> bytes: