Fix T60401: Shape key's from pointer being set to evaluated CoW ID.

Not sure exactly why this happened for 'apply as shape' and not in other
cases (did not took time to fully trace what happens there). But in any
case, `BKE_key_evaluate_object_ex()` can be called from a fair amount of
places, including during depsgraph evaluation, so setting back key's
owner here is plain wrong in CoW era.

source/blender/blenkernel/intern/key.c

@@ -1333,9 +1333,6 @@ float *BKE_key_evaluate_object_ex(
 		out = (char *)arr;
 	}
 
-	/* prevent python from screwing this up? anyhoo, the from pointer could be dropped */
-	key->from = (ID *)ob->data;
-
 	if (ob->shapeflag & OB_SHAPE_LOCK) {
 		/* shape locked, copy the locked shape instead of blending */
 		KeyBlock *kb = BLI_findlink(&key->block, ob->shapenr - 1);