Tests: Use `assertSame()` in `WP_Customize_Nav_Menu_Item_Setting` tests. #29272

Job	Run time
QUnit Tests / Run QUnit tests	1m 24s
Slack Notifications / Prepare notifications	4s
Slack Notifications / Success notifications	4s
Slack Notifications / Failure notifications	0s
Slack Notifications / Cancelled notifications	0s
Slack Notifications / Fixed notifications	0s
Failed workflow tasks	0s
	1m 32s

Navigation Menu