sns-sqs-cdk: Update aws-cdk-lib

[kakakakakku]

Issue #, if available:
N/A

Description of changes:
Hi😀 Thanks for the useful patterns!

To keep this pattern maintainable, I updated the aws-cdk-lib.

Check

cdk deploy completed successfully and works good.

$ aws sns publish --topic-arn arn:aws:sns:ap-northeast-1:000000000000:SnsSqsCdkStack-MySnsTopicCB85459E-kpxGsvCIpoiW --subject testSubject --message testMessage
{
    "MessageId": "6078b185-e81b-502f-bc90-d30bbef98020"
}

$ aws sqs receive-message --queue-url https://sqs.ap-northeast-1.amazonaws.com/000000000000/SnsSqsCdkStack-MySqsQueue317E6770-YFVaQxGaouvC
{
    "Messages": [
        {
            "MessageId": "5e2d65f8-7cd3-4a06-8c4b-d38f3b688921",
            "ReceiptHandle": "xxxxx",
            "MD5OfBody": "d8c38f5b66a0dddc2ada0f21416bb5d5",
            "Body": "{\n  \"Type\" : \"Notification\",\n  \"MessageId\" : \"6078b185-e81b-502f-bc90-d30bbef98020\",\n  \"TopicArn\" : \"arn:aws:sns:ap-northeast-1:000000000000:SnsSqsCdkStack-MySnsTopicCB85459E-kpxGsvCIpoiW\",\n  \"Subject\" : \"testSubject\",\n  \"Message\" : \"testMessage\",\n  \"Timestamp\" : \"2026-05-25T13:54:42.333Z\",\n  \"SignatureVersion\" : \"1\",\n  \"Signature\" : \"xxx\",\n  \"SigningCertURL\" : \"https://sns.ap-northeast-1.amazonaws.com/SimpleNotificationService-7506a1e35b36ef5a444dd1a8e7cc3ed8.pem\",\n  \"UnsubscribeURL\" : \"https://sns.ap-northeast-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:ap-northeast-1:000000000000:SnsSqsCdkStack-MySnsTopicCB85459E-kpxGsvCIpoiW:0dd1824f-2361-40fa-b80f-d3f73fcc64ed\"\n}"
        }
    ]
}

Thank you😀

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[kakakakakku]

from: https://pypi.org/project/aws-cdk-lib/2.13.0/
to: https://pypi.org/project/aws-cdk-lib/2.257.0/

[kakakakakku]

note: add_subscription() automatically adds an equivalent SQS resource policy, so this block is redundant😀