Case T-648/21: Judgment of the General Court of 20 September 2023 — YD v FRA (Civil service — Temporary staff — Staff of the FRA — Withdrawal of the United Kingdom from the European Union — Loss of nationality of a Member State — Contract for an indefinite period — Termination of the contract — Article 47(c)(ii) of the CEOS — Application for an exception to the condition of engagement laid down in Article 12(2)(a) of the CEOS — Refusal to grant an exception — Right to be heard — Principle of impartiality — Legal certainty — Principle of non-discrimination — Interests of the service — Duty of care — Manifest error of assessment)