### 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_
return {
            "topic_arn": subscriber["TopicArn"],
            "endpoint": subscriber["Endpoint"],
            "message_content": message_context.message_content(subscriber["Protocol"]),
        }
class FirehoseTopicPublisher(TopicPublisher):
    """
    The Firehose publisher is responsible for publishing the SNS message to a subscribed Firehose delivery stream.
    This allows you to "fan out Amazon SNS notifications to Amazon Simple Storage Service (Amazon S3), Amazon Redshift,
    Amazon OpenSearch Service (OpenSearch Service), and to third-party service providers."
    See https://docs.aws.amazon.com/sns/latest/dg/sns-firehose-as-subscriber.html
    """
    def _publish(self, context: SnsPublishContext, subscriber: SnsSubscription):
        message_body = self.prepare_message(context.message, subscriber)
        try:
            firehose_client = aws_stack.connect_to_service("firehose")
            endpoint = subscriber["Endpoint"]
            if endpoint:
                delivery_stream = extract_resource_from_arn(endpoint).split("/")[1]
                firehose_client.put_record(
                    DeliveryStreamName=delivery_stream, Record={"Data": to_bytes(message_body)}
                )
                store_delivery_log(context.message, subscriber, success=True)
        except Exception as exc:
            LOG.info(
                "Received error on sending SNS message, putting to DLQ (if configured): %s", exc
            )
            
            
class SmsPhoneNumberPublisher(EndpointPublisher):