### 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_
self,
        sns_client,
        sns_create_topic,
        snapshot,
    ):
        topic_arn = sns_create_topic()["TopicArn"]
        fake_topic_arn = topic_arn + "fake-topic"
        with pytest.raises(ClientError) as e:
            sns_client.publish_batch(
                TopicArn=fake_topic_arn,
                PublishBatchRequestEntries=[
                    {
                        "Id": "1",
                        "Message": "Test Message with two attributes",
                        "Subject": "Subject",
                    }
                ],
            )
        snapshot.match("publish-batch-no-topic", e.value.response)
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(
        paths=[
            "$.topic-attrs.Attributes.DeliveryPolicy",
            "$.topic-attrs.Attributes.EffectiveDeliveryPolicy",
            "$.topic-attrs.Attributes.Policy.Statement..Action",  # S
            "$..Messages..Attributes.SequenceNumber",
            "$..Successful..SequenceNumber",  # n