Issue 385 - Update scene view in global_flat_shading()

[hdoi5324]

blendergt task crashes at globat_flat_shading(). See issue 385

Updating the scene after removing 'Atmosphere' and 'Atmosphere Fine' objects seems to fix it. Add bpy.context.view_layer.update() after removing these objects

Also remove 'liquid' and 'liquid_fine' for global_flat_shading.

[araistrick]

I am testing this and may tweak / merge it. thanks for the contribution and sorry for being slow in getting to it

FYI I will most likely keep liquid included in ground truth by default, but I will maybe make your liquid change into a gin-configurable kwarg. in future we should probably have a rich config system for this, because it is unclear whether glass / liquids etc should be included in depthmaps.

[araistrick]

I have cherrypicked 6ca2528 to be included in my v1.12.1 patch. I will close this PR once that is merged, and we consider the liquid-in-groundtruth to be a separate issue if you want to reopen it / file another PR.

thanks for the contribution(s)! i will get to the others asap, likely after the holidays.

[araistrick]

Included your GT fix as part of 1.12.1. thanks again. I will credit you in the github release for this verison which will be created ~Dec26