Fix #131316: Edit overlays rendered for geometry instances

Geometry instances shouldn't be drawn with cage overlays or other
edit mode overlays since they don't necessarily correspond to original
data. In this case the draw manager thought they were in edit mode
because the object data is copied from the instance parent-- we need
_some_ object for rendering.

Pull Request: https://projects.blender.org/blender/blender/pulls/132081

source/blender/draw/intern/draw_manager_c.cc

@@ -594,7 +594,9 @@ static void duplidata_key_free(void *key)
     drw_batch_cache_generate_requested(dupli_key->ob);
   }
   else {
+    /* Geometry instances shouldn't be rendered with edit mode overlays. */
     Object temp_object = blender::dna::shallow_copy(*dupli_key->ob);
+    temp_object.mode = OB_MODE_OBJECT;
     blender::bke::ObjectRuntime runtime = *dupli_key->ob->runtime;
     temp_object.runtime = &runtime;