[ECR] [request]: Auto cleanup for ECR pull through cache

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**Tell us about your request**
Implement an lifecycle rule feature to removed images based on their last download.

**Which service(s) is this request for?**
Fargate, ECS, EKS, ECR

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
The images aren't cleaned up automatically. Therefore a lot of storage is wasted.

**Are you currently working around this issue?**
We are deploying some custom lambda function which delete old images.

**Additional context**
Anything else we should know?

**Attachments**
If you think you might have additional information that you'd like to include via an attachment, please do - we'll take a look. (Remember to remove any personally-identifiable information.)

No repository files, tests, or entry points are mentioned. Start by reviewing the ECR pull-through cache behavior and the custom Lambda workaround described in the issue. Done means an ECR lifecycle rule can remove images based on their last download, covering the listed container services.

Written by the indexing model from the issue text.