### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When starting the transcription job in response job object is null:

<img width="1154" alt="Screenshot 2023-04-03 at 09 21 09" src="https://user-images.githubusercontent.com/454412/229447066-1671f811-da49-478d-bf24-252f30b17699.png">


### Expected Behavior

Response from the real AWS stack - job object is not null

<img width="1161" alt="Screenshot 2023-04-03 at 09 30 13" src="https://user-images.githubusercontent.com/454412/229441498-06125248-3b68-4679-8204-0163e8245db6.png">


### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

Using test containers, reproducing project can be found here:

https://github.com/kkocel/local-stack-transcribe-repro

### Environment

```markdown
- OS: macOS
- LocalStack: latest
```


### Anything else?

_No response_
service: str,
        region: str = None,
        signer_factory: Callable[
            [botocore.credentials.Credentials, str, str], botocore.auth.BaseSigner
        ] = botocore.auth.SigV4QueryAuth,
        endpoint_url: str = None,
    ):
        region = region or boto3_session.region_name
        region = region or config.DEFAULT_REGION
        credentials = boto3_session.get_credentials()
        creds = credentials.get_frozen_credentials()
        if not endpoint_url:
            if os.environ.get("TEST_TARGET", "") == "AWS_CLOUD":
                
                resolver: EndpointResolver = boto3_session._session.get_component(
                    "endpoint_resolver"
                )
                endpoint_url = "https://" + resolver.construct_endpoint(service, region)["hostname"]
            else:
                endpoint_url = config.get_edge_url()
        return SigningHttpClient(signer_factory(creds, service, region), endpoint_url=endpoint_url)
    return factory
@pytest.fixture(scope="class")
def dynamodb_client(aws_client):