Case C-795/19: Judgment of the Court (Second Chamber) of 15 July 2021 (request for a preliminary ruling from the Riigikohus — Estonia) — XX v Tartu Vangla (Reference for a preliminary ruling — Social policy — Equal treatment in employment and occupation — Directive 2000/78/EC — Prohibition of discrimination on grounds of disability — Article 2(2)(a) — Article 4(1) — Article 5 — National legislation laying down requirements in respect of the auditory acuity of prison officers — Failure to meet the standards of sound perception required — Absolute bar to remaining in employment)