Remove comments that repeat association operations

src/scene/modify.rs

@@ -730,10 +730,6 @@ impl Scene {
         // Complete group copies record their new Group objects and dictionary
         // entry as targeted object deltas inside copy_complete_groups.
         self.copy_complete_groups(&handle_map);
-        // A dimension copied together with everything it measures (its
-        // viewport, its block path and its source) keeps an association, with
-        // every handle remapped onto the copies. Copied on its own it keeps
-        // none — see `copy_dimension_associations`.
         self.copy_dimension_associations(&handle_map);
         // The copies are new handles (natural memo misses, tessellated fresh)
         // and reference only already-cached blocks — no block defn changes.