Case C-598/19: Judgment of the Court (Fifth Chamber) of 6 October 2021 (request for a preliminary ruling from the Tribunal Superior de Justicia del País Vasco — Spain) — Confederación Nacional de Centros Especiales de Empleo (Conacee) v Diputación Foral de Gipuzkoa (Reference for a preliminary ruling — Public procurement — Directive 2014/24/EU — Article 20 — Reserved contracts — National legislation reserving the right to participate in certain public procurement procedures to Social initiative special employment centres — Additional conditions not provided for by the directive — Principles of equal treatment and proportionality)