Zaribo v2 Rigid Mount - fix M2.5x8 screws

The original Dragon hotend comes with M2.5x8 screws. The Zaribo v2 instead comes with an M3 screw-mount.  This .3mf contains negative cylinders in the appropriate places to remove the space that prevents these screws from mounting correctly.

It is not pixel perfect, but perfectly does the job.

I suggest to print it with 4 perimeters for extra rigidity