setup tracing subscriber properly so it initializes log as well

src/bin/mod.rs

···
         .with(stderr_log)
         .with(otel);
 
-    tracing::subscriber::set_global_default(subscriber).expect("to set global tracing subscriber");
+    use tracing_subscriber::util::SubscriberInitExt;
+    subscriber.init();
 }
 
 #[allow(dead_code)]