Fix a test after recent changes to lib (in)directly linked ID handling.

rB133dde41bb5b changed handling of (in)directly linked status handling
for IDs, now IDs that are not directly linked get proper status and
handling on file save. this broke parts of the `pyapi_idprop_datablock`
tests.

tests/python/bl_pyapi_idprop_datablock.py

@@ -146,6 +146,8 @@ def check_lib_linking():
     with bpy.data.libraries.load(lib_path, link=True) as (data_from, data_to):
         data_to.scenes = ["Scene_lib"]
 
+    bpy.context.window.scene = bpy.data.scenes["Scene_lib"]
+
     o = bpy.data.scenes["Scene_lib"].objects['Unique_Cube']
 
     expect_false_or_abort(o.prop_array[0].test_prop == bpy.data.scenes["Scene_lib"].objects['Light'])
@@ -158,9 +160,10 @@ def check_lib_linking():
 def check_linked_scene_copying():
     # full copy of the scene with datablock props
     bpy.ops.wm.open_mainfile(filepath=test_path)
-    bpy.context.window.scene = bpy.data.scenes["Scene_lib"]
     bpy.ops.scene.new(type='FULL_COPY')
 
+    bpy.context.window.scene = get_scene("lib.blend", "Scene_lib")
+
     # check save/open
     bpy.ops.wm.save_as_mainfile(filepath=test_path)
     bpy.ops.wm.open_mainfile(filepath=test_path)