Fix #134039: Alembic procedural proxy mesh should be owned by GeometrySet

When using Alembic procedurals, the Mesh Sequence Cache attempts to
replace the original geometry with a plain old cube. However, it never
frees this new cube geometry. Transfer ownership to the underlying
GeometrySet instead.

Investigating the scenario also showed that the `~AlembicProcedural`
dtor was removing an item from the `nodes` vector while iterating over
it, which triggers debug asserts on at least MSVC. I believe the removal
is unnecessary since this is the dtor and ASAN appears clean now.

Pull Request: https://projects.blender.org/blender/blender/pulls/134085

intern/cycles/scene/alembic.cpp

@@ -819,8 +819,6 @@ AlembicProcedural::~AlembicProcedural()
         geometries_set.insert(abc_object->get_object()->get_geometry());
       }
     }
-
-    delete_node(abc_object);
   }
 
   /* We may delete a Procedural before rendering started, so scene_ can be null. */

source/blender/modifiers/intern/MOD_meshsequencecache.cc

@@ -208,7 +208,7 @@ static void modify_geometry_set(ModifierData *md,
           pointcloud->bounds_min_max(), pointcloud->mat, pointcloud->totcol);
     }
 
-    *geometry_set = bke::GeometrySet::from_mesh(bbox, bke::GeometryOwnershipType::Editable);
+    *geometry_set = bke::GeometrySet::from_mesh(bbox);
     return;
   }