### 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_
"Action": "Publish",
                "Version": "2010-03-31",
                "TopicArn": topic_arn,
                "Message": message,
            },
        )
        json_response = xmltodict.parse(response.content)
        json_response["PublishResponse"].pop("@xmlns")
        json_response["PublishResponse"]["ResponseMetadata"][
            "HTTPStatusCode"
        ] = response.status_code
        json_response["PublishResponse"]["ResponseMetadata"]["HTTPHeaders"] = dict(response.headers)
        snapshot.match("post-request", json_response)
        assert response.status_code == 200
        assert b"<PublishResponse" in response.content
        rs = sqs_client.receive_message(QueueUrl=queue_url, VisibilityTimeout=0, WaitTimeSeconds=5)
        snapshot.match("messages", rs)
        msg_body = json.loads(rs["Messages"][0]["Body"])
        assert msg_body["TopicArn"] == topic_arn
        assert msg_body["Message"] == message
    @pytest.mark.only_localstack
    def test_multiple_subscriptions_http_endpoint(
        self, sns_client, sns_create_topic, sns_subscription
    ):
        # c
        topic_arn = sns_create_topic()["TopicArn"]
        # b
        _requests = queue.Queue()
        # c
        def handler(request):