Can not destroy a db [Error: Cycle: aws_rds_cluster_instance]

[xzGithu]

Terraform Version

Run terraform -v to show the version. If you are not running the latest version of Terraform, please upgrade because your issue may have already been fixed.

terraform 1.1.5

provider version

postgresql = {
source = "cyrilgdn/postgresql"
version = "~> 1.20.0"
}

terraform code

provider "postgresql" {
host = aws_rds_cluster_instance.rio-dev[0].endpoint
username = var.rds_master_username
password = var.rds_master_password

}

resource "postgresql_database" "rio_dbs" {
for_each = toset( var.rds_application_database_names )
name = each.key
owner = var.rds_master_username
}

I set the rds_application_database_names to ['a','b','c'] and the 3 db created, but when I update the variable to ['a','b'] and run the terraform again , I came into such issue
│ Error: Cycle: aws_rds_cluster_instance.rio-dev[0], provider"[registry.terraform.io/cyrilgdn/postgresql"], postgresql_database.rio_dbs["c"] (destroy)

expected result

the db c is destroyed