Fix getting frametimes for behavior box

src/npc_mvr/mvr.py

@@ -161,7 +161,7 @@ def frame_times(self) -> dict[CameraName, npt.NDArray[np.float64]]:
         if self.is_behavior_box:
             return {
                 get_camera_name("behavior"): get_video_frame_times_for_behavior_session(
-                    self.video_paths["behavior"],
+                    self,
                     self.task_data_or_path,
                 )
             }