### 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_
type="Notification",
            message=message,
            message_attributes=message_attributes,
            message_deduplication_id=message_deduplication_id,
            message_group_id=message_group_id,
            message_structure=message_structure,
            subject=subject,
        )
        publish_ctx = SnsPublishContext(
            message=message_ctx, store=store, request_headers=context.request.headers
        )
        if is_endpoint_publish:
            self._publisher.publish_to_application_endpoint(
                ctx=publish_ctx, endpoint_arn=target_arn
            )
        elif phone_number:
            self._publisher.publish_to_phone_number(ctx=publish_ctx, phone_number=phone_number)
        else:
            
            
            
            self._publisher.publish_to_topic(publish_ctx, topic_or_target_arn)
        return PublishResponse(MessageId=message_ctx.message_id)
    def subscribe(
        self,
        context: RequestContext,
        topic_arn: topicARN,
        protocol: String,
        endpoint: String = None,
        attributes: SubscriptionAttributesMap = None,