Auto-delete old build files from S3

**Is your feature request related to a problem? Please describe.**

I saw that the S3 bucket for my project is getting rather large. I looked in there and it appears that all of my old builds are persisted in there.

**Describe the solution you'd like**

Is it possible to auto-purge old builds? A similar setup I’ve seen in other tools is something like “Only keep the 10 most recent builds”

**Describe alternatives you've considered**

I could manually delete old build files. I don’t know if this might cause issues within the AWS Amplify Console or some other Amplify-related tools.