### 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_
subscription_arn = subscription["SubscriptionArn"]
            subscription_obj = sns_backend.subscription_status[subscription_arn]
            assert subscription_obj["Status"] == "Not Subscribed"
            _token = subscription_obj["Token"]
            sns_client.confirm_subscription(TopicArn=topic_arn, Token=_token)
            assert subscription_obj["Status"] == "Subscribed"
        retry(check_subscription, retries=PUBLICATION_RETRIES, sleep=PUBLICATION_TIMEOUT)
    @pytest.mark.aws_validated
    def test_sqs_topic_subscription_confirmation(
        self, sns_client, sns_create_topic, sqs_create_queue, sns_create_s, snapshot
    ):
        topic_arn = sns_create_topic()["TopicArn"]
        queue_url = sqs_create_queue()
        subscription_attrs = sns_create_s(topic_arn=topic_arn, queue_url=queue_url)
        def check_subscription():
            nonlocal subscription_attrs
            if not subscription_attrs["PendingConfirmation"] == "false":
                subscription_arn = subscription_attrs["SubscriptionArn"]
                subscription_attrs = sns_client.get_subscription_attributes(
                    SubscriptionArn=subscription_arn
                )["Attributes"]
            else:
                snapshot.match("subscription-attrs", subscription_attrs)
            return subscription_attrs["PendingConfirmation"] == "false"
        # S