Some enum names were changed/removed in OptiX 7.4, so some changes are necessary to
make things compile still.
In addition, OptiX 7.4 also adds built-in support for catmull-rom curves, so it is no longer
necessary to convert the catmull-rom data to cubic bsplines first, and has endcaps disabled
by default now, so can remove the special handling via any-hit programs that filtered them
out before.
Differential Revision: https://developer.blender.org/D13351