If I run this very simple Rust program and attach with gdb or check with htop, I see that it creates 16 threads (exactly how many cores I have on the machine by the way) even though I am passing in the option to run single threaded to the tokio main. How come? What are these threads doing? Can I get rid of them?

 #[tokio::main(flavor = "current_thread")]
    async fn main() -> anyhow::Result<()> {
        loop {
            tokio::time::sleep(Duration::from_secs(1)).await;
        }
    }