Increase sleep duration before closing zenoh session to 2 secs

We still saw some missed stop messages on the CI with the 1sec delay.

apis/rust/node/src/communication/zenoh.rs

@@ -60,7 +60,7 @@ impl Drop for ZenohCommunicationLayer {
         //
         // TODO: create a minimal example to reproduce the dropped messages
         // and report this issue in the zenoh repo
-        std::thread::sleep(Duration::from_secs_f32(1.0));
+        std::thread::sleep(Duration::from_secs_f32(2.0));
     }
 }