This fixes two things:
* Pass the evaluated object into `BKE_object_as_kdtree` instead of the original
one. `BKE_object_as_kdtree` uses functions on the object which are only
expected to be executed on evaluated objects, such as
`BKE_object_get_mesh_deform_eval`. Note that this is the only place where
`BKE_object_as_kdtree` is used.
* Tag depsgraph at the end of setting parent. This way,
`BKE_object_get_evaluated_mesh` will return the correct mesh instead of null.
It was returning null because it the object is not in a fully evaluated state
if it just has been tagged as requiring an update.
Pull Request: https://projects.blender.org/blender/blender/pulls/126086
29edcef5c9