VDB files would fail to render in HIP-RT because NanoVDB wasn't
enabled when compiling HIP-RT kernels, resulting in NanoVDB textures
not being sampled and a blank result being returned instead.
The fix is to enable NanoVDB when compiling HIP-RT kernels.
Ref: #125086
Pull Request: https://projects.blender.org/blender/blender/pulls/127384