### 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_
new_payload = {}
    for k, v in payload.items():
        if isinstance(v, Dict):
            new_payload[k] = read_streams(v)
        elif isinstance(v, StreamingBody):
            new_payload[k] = to_str(v.read())
        else:
            new_payload[k] = v
    return new_payload
class TestLambdaAPI:
    @pytest.mark.only_localstack
    def test_create_lambda_function(self, lambda_client):
        """Basic test that creates and deletes a Lambda function"""
        func_name = f"lambda_func-{short_uid()}"
        kms_key_arn = f"arn:{aws_stack.get_partition()}:kms:{aws_stack.get_region()}:{TEST_AWS_ACCOUNT_ID}:key11"
        vpc_config = {
            "SubnetIds": ["subnet-123456789"],
            "SecurityGroupIds": ["sg-123456789"],
        }