Make single-threaded as default

src/main.rs

@@ -9,7 +9,7 @@ use tokio::{
 use tower_http::{timeout::TimeoutLayer, trace::TraceLayer};
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
-#[tokio::main]
+#[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<(), std::io::Error> {
     tracing_subscriber::registry()
         .with(tracing_subscriber::EnvFilter::from_env("LOG_LEVEL"))