In T93382, the problem was that the Blender-side rendering code was still generating the subsurface passes because the old render pass flags were set, even though Cycles doesn't generate them anymore. After a closer look, it turns out that the entire hardcoded pass creation code can be removed. We already have an Engine API function to query the list of render passes from the engine, so we might as well just call that and create the returned passes. Turns out that Eevee already did this anyways. On the Cycles side, it allows to deduplicate a lot of `BlenderSync::sync_render_passes`. Before, passes were defined in engine.py and in sync.cpp. Now, all passes that engine.py returns are created automatically, so sync.cpp only needs to handle a few special cases. I'm not really concerned about affecting external renderer addons, since they already needed to handle the old "builtin passes" in their Engine API implementation anyways to make them show up in the compositor. So, unless they missed that for like 10 releases, they should not notice any difference. Differential Revision: https://developer.blender.org/D16295