61bda71083
Instead of calling `BKE_nlastrip_new()` (which, due to backward compat reasons automatically picks a slot), the Push Down operator now calls `BKE_nlastrip_new_for_slot()`, which explicitly assigns the given slot. On top of that, the frame range of the slot is used to set the strip's frame range (instead of the range of the entire Action). Pull Request: https://projects.blender.org/blender/blender/pulls/128444