Sometime throughout development some checks got lost during refactor.
This change makes it so that if OIDN is not supported on the current
CPU Cycles will report an error and stop rendering. This behavior is
similar to when an OptiX denoiser is requested and there is no OptiX
compatible device available.
The easiest way to verify this change is to force return false from
the `openimagedenoise_supported()`.
Fixes Cycles part of the T94127.
Differential Revision: https://developer.blender.org/D13944