fix step duplication

src/Runner.Worker/Dap/DapDebugSession.cs

@@ -1770,8 +1770,8 @@ namespace GitHub.Runner.Worker.Dap
             }
 
             // Reset the step manipulator to match the restored state
-            // It will be re-initialized when the restored step starts
             _stepManipulator?.ClearChanges();
+            _stepManipulator?.TrimCompletedSteps(checkpointIndex);
 
             // Store restored checkpoint for StepsRunner to consume
             _restoredCheckpoint = checkpoint;