chore(backend): Migrate to S3 native state locking

[jongwooo]

This pull request updates the backend configuration in the backend.tf file to improve state locking and security.

Key Changes

• Migration to S3 Native State Locking
  Replaced the legacy dynamodb_table option with the new use_lockfile = true setting.
  This enables S3 native state locking introduced in Terraform v1.10+, allowing for simplified locking without relying on DynamoDB.

• Why This Matters
  The previous DynamoDB-based locking mechanism is now deprecated.
  S3 native state locking improves maintainability and reduces the need for external dependencies like DynamoDB, enhancing both security and simplicity.

Backend configuration updates:

• backend.tf: Replaced dynamodb_table with use_lockfile = true to adopt S3 native state locking.

[Copilot]

Pull Request Overview

This PR migrates the Terraform backend configuration from DynamoDB-based state locking to S3 native state locking, removing the dependency on DynamoDB for lock management.

• Replaced deprecated dynamodb_table configuration with use_lockfile = true
• Adopts S3 native state locking feature introduced in Terraform v1.10+
• Simplifies infrastructure by removing DynamoDB dependency

Comments suppressed due to low confidence (1)

backend.tf:7

• The use_lockfile option for S3 backend state locking was introduced in Terraform v1.10, but as of my knowledge cutoff in January 2025, Terraform v1.10 has not been released yet. Please verify that you are using a compatible Terraform version that supports this feature.

    use_lockfile = true