fix: use cloudwatch retention policy

[infracost-autofix]

💰 Infracost opened this pull request as part of the following campaign:

Policy: AWS Cloudwatch - consider using a retention policy to reduce storage costs Use a retention policy to avoid retaining logs indefinitely and accumulating storage costs. For example, if an application generates 5GB of logs daily, in a year without retention, you'd store 1.8TB of logs. In the AWS US East (N. Virginia) region, where storage costs $0.03 per GB per month, you'll incur a cumulative yearly cost of ~$802. This cost will continually grow as more logs are added.

Risk: Medium Improper retention could delete logs needed for compliance or debugging.

Deployment details: no downtime required, see AWS docs for details Retention policies apply in‑place to log groups without service disruption. AWS may take up to 72 hours to delete expired events after changing retention.

Next steps:
✅ Deploy this change before the campaign deadline: June 31
💬 Doesn't apply? Close the PR with a comment
🛠️ Needs changes? Check out the branch to rebase or adjust

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}