[skip e2e] Add comment for globalSealedSegmentManager (#14444)

Signed-off-by: Nbigsheeper <yihao.dai@zilliz.com>

internal/querynode/global_sealed_segment_manager.go

@@ -107,6 +107,7 @@ func (g *globalSealedSegmentManager) removeGlobalSegmentIDsByPartitionIds(partit
 	}
 }
 
+// close would free globalSealedSegmentManager
 func (g *globalSealedSegmentManager) close() {
 	g.mu.Lock()
 	defer g.mu.Unlock()