Speed up rotation optimizer

- No float to double conversion
- Solving issue of random (very similar) results due to the parallel summation of floats

src/libslic3r/SLA/Rotfinder.hpp

@@ -35,7 +35,7 @@ Vec2d find_best_rotation(
         );
 
 double get_model_supportedness(const SLAPrintObject &mesh,
-                               const Transform3d & tr);
+                               const Transform3f & tr);
 
 } // namespace sla
 } // namespace Slic3r