Configure Terraform S3 backend with native state locking (use_lockfile) without DynamoDB

Steps

1. Upgrade Terraform to 1.11 or later where native S3 state locking (`use_lockfile`) is generally available; in 1.10 it was experimental.
2. In the S3 backend configuration block set `use_lockfile = true`; remove or stop adding the `dynamodb_table` argument (it is deprecated in 1.11 and will be removed in a future version).
3. Ensure the S3 bucket has versioning enabled; Terraform uses S3 conditional writes (`If-None-Match`) to create a `.tflock` file alongside the state file, requiring S3 object conditional write support (available on standard S3 buckets).
4. The lock file is named `<state-key>.tflock`; ensure the IAM policy for Terraform's identity includes `s3:PutObject`, `s3:GetObject`, and `s3:DeleteObject` on both `*.tfstate` and `*.tflock` object paths.
5. Test locking by running two simultaneous `terraform plan` operations against the same state; the second should fail with a lock error until the first completes.
6. For teams migrating from DynamoDB locking, remove the DynamoDB table reference from the backend config and the DynamoDB IAM permissions after verifying native locking works correctly.