Problem here is that when selecting/activating an object in a different
scene in the Outliner, the Outliner will automatically switch scenes via
`WM_window_set_active_scene` however the `view_layer` was untouched and
as a consequence `BKE_view_layer_synced_ensure` gets the right scene but
the "wrong" viewlayer [which makes it not do its thing properly]
To solve, now use the new active viewlayer after having switched scenes.
NOTE this also solves a couple of other asserts elsewhere (when not
deleting, just selecting/activating could assert on
`DEG_is_evaluated_object(ob)`)
Philipp Oeser