### 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_
try:
                
                aws_client.sns.set_subscription_attributes(
                    SubscriptionArn=subscription_arn,
                    AttributeName="RawMessageDelivery",
                    AttributeValue="true",
                )
                raise Exception("Subscription is not deleted")
            except ClientError as e:
                assert e.response["Error"]["Code"] == "NotFound"
                assert e.response["ResponseMetadata"]["HTTPStatusCode"] == 404
                snapshot.match("sub-not-found", e.response)
        retry(check_subscription_deleted, retries=10, sleep_before=0.2, sleep=3)
        subscriptions_by_topic = aws_client.sns.list_subscriptions_by_topic(TopicArn=topic_arn)
        snapshot.match("subscriptions-for-topic-after-unsub", subscriptions_by_topic)
        assert len(subscriptions_by_topic["Subscriptions"]) == 0
    @markers.aws.validated
    @markers.snapshot.skip_snapshot_verify(
        paths=[
            "$.invalid-json-redrive-policy.Error.Message",  
            "$.invalid-json-filter-policy.Error.Message",  
        ]
    )
    def test_validate_set_sub_attributes(