Remove uppercase enforcement of environment variables

[pcassaretto-cmc]

Currently environment vars must be uppercase, which prevents us from populating terraform input variables directly with this action. For example, we cannot do TF_VAR_secret_1 directly with this action and then need an intermediate action to take this output and set the correct terraform environment variable.

I think this should be allowed given the enormous popularity of terraform. Can't see any documented reasoning why you force the name to uppercase here https://github.com/aws-actions/aws-secretsmanager-get-secrets/blob/main/src/utils.ts#L189C54-L189C65

[jbct]

Thank you for the request, we will look into this.