### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

There is an issue with `get-object-attributes` command which results in below error always: 
`aws --endpoint-url=http://localhost:4566 s3api get-object-attributes --bucket s3mock --key 20.txt --object-attributes "ObjectSize"`
````

> Response:  Unable to parse response (syntax error: line 1, column 0), invalid XML received. Further retries may succeed:
b'98\n5\n'
````

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

#### Using docker-compse.yaml to start localstack

docker-compse.yaml:

```
localstack:
    image: localstack/localstack:latest
    ports:
      - '4563-4599:4563-4599'
      - '8055:8080'
    environment:
      - SERVICES=s3
      - DEBUG=1
      - LS_LOG=error
      - DATA_DIR=/tmp/localstack/data
      - AWS_DEFAULT_REGION=eu-west-1
      # - EDGE_PORT=4566
    volumes:
      - "./.localstack:/tmp/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"
```

#### cli commands to reproduce the issue

1. Create a Bucket: `aws --endpoint-url=http://localhost:4566 s3 mb s3://s3mock`
2. Create an Object: `aws --endpoint-url=http://localhost:4566 s3 cp data/20.txt s3://s3mock`

File 20.txt content are 2-digit numbers separated by newline.

3. get-object-attributes for object 20.txt :
```

 aws --endpoint-url=http://localhost:4566 s3api get-object-attributes --bucket s3mock --key 20.txt --object-attributes "ObjectSize"

```
Results in error:

> Unable to parse response (syntax error: line 1, column 0), invalid XML received. Further retries may succeed:
b'98\n5\n'



### Environment

```markdown
- OS:Mac 12.x
- LocalStack:latest
- Node 14
```


### Anything else?

_No response_
"""
    Error which indicates that the given data is not compliant with the service's specied.
    This usually results in a response with an HTTP 4xx status code (client error).
    """
    pass
class OperationNotFoundParserError(ProtocolParserError):
    """
    Error which indicates that the given data cannot be matched to a specific operation.
    The request is likely _not_ meant to be handled by the ASF service provider itself.
    """
    pass
def _handle_exceptions(func):
    """
    Decorator which handles the exceptions raised by the parser. It ensures that all exceptions raised by the public
    methods of the parser are instances of RequesrError.
    :param func: to wrap in order to add the exception handling
    :n: wrapped function
    """
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        try:
            n func(*args, **kwargs)
        except RequesrError:
            raise
        except Exception as e:
            raise UnknownParserError(
                "An unknown error occurred when trying to parse the request."
            ) from e
    n wrapper
class Requesr(abc.ABC):