fix: wait for compaction task to finish (#1783)

src/datanode/src/instance.rs

@@ -354,7 +354,7 @@ impl Instance {
 fn create_compaction_scheduler<S: LogStore>(opts: &DatanodeOptions) -> CompactionSchedulerRef<S> {
     let picker = SimplePicker::default();
     let config = SchedulerConfig::from(opts);
-    let handler = CompactionHandler::new(picker);
+    let handler = CompactionHandler { picker };
     let scheduler = LocalScheduler::new(config, handler);
     Arc::new(scheduler)
 }