[terraform] Add blob cleanup cron task

Summary:
Created an ECS task definition for cleanup job and used AWS EventBridge Scheduler to run it every 24 hours.

Depends on D9414

Test Plan: Tested on staging during the weekend. The cleanup job is being run periodically and succeeds.

Reviewers: varun, michal, jon

Reviewed By: michal

Subscribers: ashoat, tomek, wyilio

Differential Revision: https://phab.comm.dev/D9415