This commit makes the rake task operational for all regions for s3. If we declare s3_endpoint as https://s3.amazonaws.com while
creating an instance of Aws::S3::Client, head_bucket fails for all s3 regions apart from us-east-1. The commit manually defines all
parameters for Aws::S3::Client apart from s3_endpoint to bypass this problem make this task usable for AWS S3.
Removing s3_endpoint from the payload means that custom endpoints like Minio/DO Spaces for will not work in the meantime and we'll
have to add support for a custom `s3_endpoint` in the future.
This commit follows up on 60790eb0.