Case C-731/21: Judgment of the Court (Eighth Chamber) of 8 December 2022 (request for a preliminary ruling from the Cour de cassation du Grand-Duché de Luxembourg — Luxembourg) — GV v Caisse nationale d’assurance pension (Reference for a preliminary ruling — Free movement of persons — Article 45 TFEU — Workers — Regulation (EU) No 492/2011 — Article 7(1) and (2) — Equal treatment — Social advantages — Survivor’s pension — Members of a civil partnership — National legislation making the grant of a survivor’s pension conditional upon the entry in the national register of a partnership that was validly concluded and registered in another Member State)