test: use tokio::time::sleep in async test poll loop (SonarCloud rust:S7488)

The multi-thread #[tokio::test] polled with a blocking std::thread::sleep,
stalling a runtime worker. Use tokio::time::sleep(..).await instead.

crates/automation/src/server.rs

@@ -1197,7 +1197,7 @@ mod tests {
                 break;
             }
             assert!(t.elapsed().as_secs() < 60, "doc_inspect never saw the finished job: {inspected}");
-            std::thread::sleep(std::time::Duration::from_millis(5));
+            tokio::time::sleep(std::time::Duration::from_millis(5)).await;
         }
     }
 }