Cases T-649/20, T-721/20 and T-767/20: Judgment of the General Court of 5 July 2023 — Clean Aviation Joint Undertaking v NG (Arbitration clause — Seventh Framework Programme for the activities of research and development (FP7) — Grant agreements — Lack of supporting documents and non-compliance with the contractual requirements for part of the declared expenses — Repayment of the sums advanced — Jurisdiction of the General Court — Admissibility — Eligible costs — Burden of proof — Interest on arrears)