Temporary workaround for high memory consumption

The ellipse and torus models both need a lot of memory during compilation. On the Windows CI, there have been warnings that the free memory is almost used up while building the sample consensus library.
The workaround is to not compile these two models at the same time, so that the peak memory consumption is lower. In the long term, we should find out why these two models need so much memory, and improve that.

sample_consensus/CMakeLists.txt

@@ -13,6 +13,7 @@ endif()
 
 set(srcs
   src/sac.cpp
+  src/sac_model_ellipse3d.cpp
   src/sac_model_circle.cpp
   src/sac_model_circle3d.cpp
   src/sac_model_cylinder.cpp
@@ -26,7 +27,6 @@ set(srcs
   src/sac_model_plane.cpp
   src/sac_model_registration.cpp
   src/sac_model_sphere.cpp
-  src/sac_model_ellipse3d.cpp
   src/sac_model_torus.cpp
 )