### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

It seems that it is possible to receive sns message in an sqs listener if there is a filterpolicy in place for null value in a message attribute, and a message is being sent without the message attribute.

### Expected Behavior

Don't recieve these type of messages

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

`sns subscribe --topic-arn "demoTopicArn"  --protocol sqs --notification-endpoint "demoSqsEndpoint" --attributes '{"RawMessageDelivery": "true"}'`
`sns set-subscription-attributes --subscription-arn demoSubsArn --attribute-name FilterPolicy --attribute-value '{"testForNull": [null,{"anything-but": ["notgood"]}]}'`
`sns publish --topic-arn demoTopicArn --message "testforrecieval"`
`sqs receive-message --queue-url  "demoUrl"`

### Environment

```markdown
- OS: macOS 13.6
- LocalStack: 2.2.0
```


### Anything else?

_No response_
), f"unexpected number of subscriptions {subscription_list}"
            tokens = []
            for _ in range(number_of_endpoints):
                request = _requests.get(timeout=2)
                request_data = request.get_json(True)
                tokens.append(request_data["Token"])
                assert request_data["TopicArn"] == topic_arn
            with pytest.raises(queue.Empty):
                # m
                _requests.get(timeout=1)
            # a
            sub_1 = subscription_list["Subscriptions"][0]
            sub_1_attrs = aws_client.sns.get_subscription_attributes(
                SubscriptionArn=sub_1["SubscriptionArn"]
            )
            assert sub_1_attrs["Attributes"]["PendingConfirmation"] == "true"
            # a
            sub_2 = subscription_list["Subscriptions"][1]
            sub_2_attrs = aws_client.sns.get_subscription_attributes(
                SubscriptionArn=sub_2["SubscriptionArn"]
            )
            assert sub_2_attrs["Attributes"]["PendingConfirmation"] == "true"
            # c
            response = aws_client.sns.confirm_subscription(TopicArn=topic_arn, Token=tokens[0])
            # a
            assert response["SubscriptionArn"] == sub_1["SubscriptionArn"]
            # a
            sub_1_attrs = aws_client.sns.get_subscription_attributes(
                SubscriptionArn=sub_1["SubscriptionArn"]
            )