fix exec hang when tx channel is full

crates/runc-shim/src/service.rs

@@ -159,6 +159,9 @@ async fn process_exits(
             if let Subject::Pid(pid) = e.subject {
                 debug!("receive exit event: {}", &e);
                 let exit_code = e.exit_code;
+                let containers = containers.clone();
+                let tx = tx.clone();
+                tokio::spawn(async move {                
                 for (_k, cont) in containers.lock().await.iter_mut() {
                     let bundle = cont.bundle.to_string();
                     // pid belongs to container init process
@@ -204,7 +207,7 @@ async fn process_exits(
                             break;
                         }
                     }
-                }
+                }});
             }
         }
         monitor_unsubscribe(s.id).await.unwrap_or_default();