AssumeRoleProvider Configuration Updates

[rcoh]

The API for AssumeRoleProvider has been updated to derive configuration from SdkConfig instead of ProviderConfig.

An example of updating code to use the new API is here.

This provides a number of advantages, most importantly, making it possible to use aws_config::load_from_env as the base set of configuration when constructing your AssumeRoleProvider.

If no custom configuration is provided, build() will fall back to using aws_config::from_env() as the source of configuration. This can be overidden with AssumeRoleProvider::builder("role...").configure(<sdkconfig>)

In either case, this means that region is not required to be set unless you need a different value than you would otherwise get from the runtime environment.

Finally:

• AssumeRoleProvider::build has been renamed build_from_provider. build() will now source a credentials provider from SdkConfig instead. You can specify SdkConfig to source defaults from with .configure(&config)
• Both of these methods are now async