### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

I am running an SNS topic that publishes to a lambda function. The localstack code reads a type byte object from the lambda function invocation payload [here](https://github.com/localstack/localstack/blob/master/localstack/services/sns/publisher.py#L187) and then tries to dump the result into json [here](https://github.com/localstack/localstack/blob/master/localstack/services/sns/publisher.py#L863) which results in the following error:
```
sns_pub_0] l.services.sns.publisher   : Unable to run Lambda function on SNS message: Object of type bytes is not JSON serializable
```

### Expected Behavior

The payload bytes should be converted to a string before being dumped to json. The error should not be thrown.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

docker-compose up
(Using the standard docker-compose.yaml)

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

```
awslocal sns publish --message file://sns/message.json --topic-arn arn:aws:sns:us-east-1:000000000000:<topic_name>
```

### Environment

```markdown
- OS: macOS Ventura 13.2.1
- LocalStack: latest
```


### Anything else?

_No response_
validate_message_attributes(message_attributes)
            
            if entry.get("MessageStructure") == "json":
                try:
                    message = json.loads(entry.get("Message"))
                    if "default" not in message:
                        raise InvalidParameterException(
                            "Invalid parameter: Message Structure - No default entry in JSON message body"
                        )
                except json.JSONDecodeError:
                    raise InvalidParameterException(
                        "Invalid parameter: Message Structure - JSON message body failed to parse"
                    )
        
        
        
        message_contexts = []
        for entry in publish_batch_request_entries:
            msg_ctx = SnsMessage.from_batch_entry(entry)
            message_contexts.append(msg_ctx)
            response["Successful"].append({"Id": entry["Id"], "MessageId": msg_ctx.message_id})
        publish_ctx = SnsBatchPublishContext(
            messages=message_contexts,
            store=store,
            request_headers=context.request.headers,
        )
        self._publisher.publish_batch_to_topic(publish_ctx, topic_arn)
        return PublishBatchResponse(**response)
    def set_subscription_attributes(