Function run_terraform_allow_exit_codes 

pub async fn run_terraform_allow_exit_codes(
    tf: &Terraform,
    command_args: Vec<String>,
    allowed_codes: &[i32],
) -> Result<CommandOutput>

Execute a Terraform command, accepting additional exit codes as success.

Terraform plan uses exit code 2 to indicate “changes present” which is not an error. Pass &[0, 2] to accept both.