Revert "Ignore alpha materials in baked light ray-tracer."
Reverts godotengine/godot#2717. This way of excluding objects is too slow, please avoid adding the triangles in the first place instead of doing it in the raytracer
Reverts godotengine/godot#2717. This way of excluding objects is too slow, please avoid adding the triangles in the first place instead of doing it in the raytracer