### 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_
_requests.put(request)
            return Response(status=429)
        number_of_endpoints = 4
        servers = []
        for _ in range(number_of_endpoints):
            server = HTTPServer()
            server.start()
            servers.append(server)
            server.expect_request("/").respond_with_handler(handler)
            http_endpoint = server.url_for("/")
            wait_for_port_open(http_endpoint)
            sns_subscription(TopicArn=topic_arn, Protocol="http", Endpoint=http_endpoint)
        # f
        subscription_list = sns_client.list_subscriptions_by_topic(TopicArn=topic_arn)
        assert subscription_list["ResponseMetadata"]["HTTPStatusCode"] == 200
        assert (
            len(subscription_list["Subscriptions"]) == number_of_endpoints
        ), f"unexpected number of subscriptions {subscription_list}"
        for _ in range(number_of_endpoints):
            request = _requests.get(timeout=2)
            assert request.get_json(True)["TopicArn"] == topic_arn
        with pytest.raises(queue.Empty):
            # m
            _requests.get(timeout=1)
        for server in servers:
            server.stop()
    @pytest.mark.only_localstack
    def test_publish_sms_endpoint(self, sns_client, sns_create_topic, sns_subscription):