Remove the profile attribute entirely

This was what was apparently breaking our Terraform actions.  I traced this to an undocumented breaking change with the AWS provider; more details can be seen here: https://discuss.hashicorp.com/t/error-error-configuring-terraform-aws-provider-failed-to-get-shared-config-profile-default/39417/2

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

terraform/staging/providers.tf

@@ -12,7 +12,6 @@ terraform {
     key     = "api.tfstate.stage"
     encrypt = "true"
     region  = "us-gov-west-1"
-    # profile = "notify-terraform-backend"
   }
 }