[Feature request] Disable Cache Files

[SimoSca]

This tool is great, but for security reasons I'd like to avoid saving the access keys in the ~/.awsume/cache/* cache files, especially since I'm hypothesizing the creation of a custom plugin that retrieves the credentials directly from my secret manager and allows me to avoid saving them in plain text in the ~/.aws/credentials file.

I think the most convenient solution would be to be able to specify a property directly at the configuration level in ~/.awsume/config.yaml.