The voronoi texture node only sets the first 3 components of the
color. The alpha value is never set. Normally this is covered
when using it in a shader node, but when directly connected to
the AOV output, the color was stored as a pure emissive color.
This resulted in incorrect colors in the viewport and image renders.
This is a partial fix for #118494
Pull Request: https://projects.blender.org/blender/blender/pulls/118497
e6eecdf614