### 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_
call_moto(context)
        store = self.get_store()
        def should_be_kept(current_subscription: SnsSubscription, target_subscription_arn: str):
            if current_subscription["SubscriptionArn"] != target_subscription_arn:
                return True
            if current_subscription["Protocol"] in ["http", "https"]:
                
                
                subscription_token = short_uid()
                message_ctx = SnsMessage(
                    type="UnsubscribeConfirmation",
                    token=subscription_token,
                    message=f"You have chosen to deactivate subscription {target_subscription_arn}.\nTo cancel this operation and restore the subscription, visit the SubscribeURL included in this message.",
                )
                publish_ctx = SnsPublishContext(
                    message=message_ctx, store=store, request_headers=context.request.headers
                )
                self._publisher.publish_to_topic_subscriber(
                    publish_ctx,
                    topic_arn=current_subscription["TopicArn"],
                    subscription_arn=target_subscription_arn,
                )
            return False
        for topic_arn, existing_subs in store.sns_subscriptions.items():
            store.sns_subscriptions[topic_arn] = [
                sub for sub in existing_subs if should_be_kept(sub, subscription_arn)
            ]
    def get_subscription_attributes(