Case T-152/21: Judgment of the General Court of 1 December 2021 — Union Syndicale Solidaires des SDIS de France et DOM/TOM v Commission (Non-contractual liability — Filing of a complaint with the Commission concerning the application of EU law — Time limit for reply — Right to good administration — Mandatory due diligence — Reasonable period — No sufficiently serious breach of a rule of law conferring rights on individuals)