### 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_
sqs_queue_arn,
        sns_subscription,
    ):
        dlq_name = f"dlq-{short_uid()}"
        dlq_url = sqs_create_queue(QueueName=dlq_name)
        dlq_arn = sqs_queue_arn(dlq_url)
        topic_arn = sns_create_topic()["TopicArn"]
        # c
        with HTTPServer() as server:
            server.expect_request("/subscription").respond_with_data(b"", 200)
            http_endpoint = server.url_for("/subscription")
            wait_for_port_open(server.port)
            subscription = sns_subscription(
                TopicArn=topic_arn, Protocol="http", Endpoint=http_endpoint
            )
            sns_client.set_subscription_attributes(
                SubscriptionArn=subscription["SubscriptionArn"],
                AttributeName="RedrivePolicy",
                AttributeValue=json.dumps({"deadLetterTargetArn": dlq_arn}),
            )
            # w
            poll_condition(lambda: len(server.log) >= 1, timeout=10)
            request, _ = server.log[0]
            event = request.get_json(force=True)
            assert request.path.endswith("/subscription")
            assert event["Type"] == "SubscriptionConfirmation"
            assert event["TopicArn"] == topic_arn
        wait_for_port_closed(server.port)
        sns_client.publish(
            TopicArn=topic_arn,