fix: remove unsupported s3Import feature name

As described here #273, s3Import is not accepted any more. I have tested with an empty string and it works.

Author: meniluca

examples/s3-import/main.tf

@@ -43,7 +43,7 @@ module "aurora" {
   iam_roles = {
     s3_import = {
       role_arn     = aws_iam_role.s3_import.arn
-      feature_name = "s3Import"
+      feature_name = ""
     }
   }