Speed up compute shutdown

libs/compute_api/src/responses.rs

@@ -52,6 +52,10 @@ pub enum ComputeStatus {
     // compute will exit soon or is waiting for
     // control-plane to terminate it.
     Failed,
+    // Wrapping up without blocking the next compute
+    // start, which might be scheduled on a different
+    // compute node
+    GracefulShutdown,
 }
 
 fn rfc3339_serialize<S>(x: &Option<DateTime<Utc>>, s: S) -> Result<S::Ok, S::Error>