Geometry Nodes: Skip calculating normals in transform node

This commit skips the eager recalculation of mesh normals in the
transform node. Often another deformation or topology-altering
operation will happen after the transform node, which means the
recalculation was redundant anyway.

In one of my test cases this made the node more than 14x faster.
Though depending on the situation the cost of updating the normals
may just be shifted elsewhere.

source/blender/nodes/geometry/nodes/node_geo_transform.cc

@@ -20,6 +20,7 @@
 
 #include "BLI_float4x4.hh"
 
+#include "DNA_mesh_types.h"
 #include "DNA_pointcloud_types.h"
 #include "DNA_volume_types.h"
 
@@ -72,7 +73,8 @@ void transform_mesh(Mesh *mesh,
   else {
     const float4x4 matrix = float4x4::from_loc_eul_scale(translation, rotation, scale);
     BKE_mesh_transform(mesh, matrix.values, false);
-    BKE_mesh_calc_normals(mesh);
+    mesh->runtime.cd_dirty_vert |= CD_MASK_NORMAL;
+    mesh->runtime.cd_dirty_poly |= CD_MASK_NORMAL;
   }
 }
 
@@ -158,7 +160,6 @@ static void transform_curve(CurveEval &curve,
                             const float3 rotation,
                             const float3 scale)
 {
-
   if (use_translate(rotation, scale)) {
     curve.translate(translation);
   }