In certain setups, nodes whose inputs are single value and whose outputs
are expected to be single value wrongly return an image. That's because
they wrongly join a pixel operation that operates on images.
To fix this, we split pixel operations by their value types. Single
value sub-trees get compiled into their own pixel operation and none
single value sub-trees get compiled into their own pixel operation.
This might unfortunately break up a long chain of pixel operations if
one of them was single value. This is solvable, but will require more
time and research, so we need to fix the bug first then look into it.
Pull Request: https://projects.blender.org/blender/blender/pulls/133701