Address VTK warnings during VRG gen pipeline

[NicerNewerCar]

https://github.com/BrownBiomechanics/SlicerAutoscoperM/blob/e036c2249dc564c2cca03914837248dae6d06666/AutoscoperM/AutoscoperM.py#L1196-L1197

Threshold Scalar Volume command line: 

C:/D/S5.5R/Slicer-build/lib/Slicer-5.5/cli-modules/Release/ThresholdScalarVolume.exe --thresholdtype Below --threshold 0 --lower 0 --upper 200 --outsidevalue 0 C:/Users/anthony.lombardi/AppData/Local/Temp/Slicer/CEBCE_vtkMRMLScalarVolumeNodeCC.nrrd C:/Users/anthony.lombardi/AppData/Local/Temp/Slicer/CEBCE_vtkMRMLScalarVolumeNodeCC.nrrd

Threshold Scalar Volume completed without errors

Input port 0 of algorithm vtkOpenGLGPUVolumeRayCastMapper (000001743BFCF2B0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCB6B0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B53BA0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCB6B0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747F036CD0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCB6B0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B53BA0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCB6B0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747F036CD0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCAB70) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B559D0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCAB70) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747E983EB0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCAB70) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B559D0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDCAB70) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747E983EB0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDC44F0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B54380) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDC44F0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747F035650) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDC44F0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageThreshold (0000017402B54380) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageMapToWindowLevelColors (000001743BDC44F0) has 0 connections but is not optional.
Input port 0 of algorithm vtkImageReslice (000001747F035650) has 0 connections but is not optional.

[amymmorton]

depreciated in favor #99