sns-sqs-terraform: Update AWS Provider to v6

[kakakakakku]

Issue #, if available:
N/A

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

To keep this pattern maintainable, I updated the AWS Provider to v6.

Check

terraform apply completed successfully and works good.

$ aws sns publish --topic-arn arn:aws:sns:us-east-1:000000000000:sns-sqs-demo-000000000000 --subject testSubject --message testMessage --region us-east-1
{
    "MessageId": "a234ba7a-20a6-56ae-b908-d8fef0ded902"
}

$ aws sqs receive-message --queue-url sns-sqs-demo-000000000000 --region us-east-1
{
    "Messages": [
        {
            "MessageId": "7060461f-4264-41f5-bcdd-3889f98ec5bf",
            "ReceiptHandle": "xxx",
            "MD5OfBody": "37546b0ac9dc24506d4d1a4f05f35414",
            "Body": "xxx"
        }
    ]
}

Thank you😀

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[kakakakakku]

[ellisms]

Thanks for the updates, @kakakakakku . I'll add this to the publishing queue.