Creates AmazonS3 object using all environmental variables for additional cases where command line parameters are not appropriate.
This makes step 4 here possible - https://docs.aws.amazon.com/sdk-for-rust/latest/dg/credproviders.html
Alternative approach may have been to add a similar command line option for AWS_CONTAINER_CREDENTIALS_RELATIVE_URI but this makes no sense to provide on a CLI given it is only to be set automatically on Fargate and EKS containers.
As from_env() looks up all relevant environmental variables, it no longer makes sense to look for them as part of the CLI option parsing, so those relevant env options are removed.
Fixes#25828
26bf912db2