Serverless adding files to S3 Bucket

I just got a billing alert from AWS S3 (which I don’t use for anything) that I had incurred a charge. When i looked into it, there is a S3 bucket called serverless that seems to hold my zipped codebase. i assume that this is meant to be a backup of every deployment but in my use case isn’t really necessary and i don’t want to be paying S3 bills for. Can anyone tell me if theses are ok to delete and if its possible to disable this feature?