flake.lock: Update
Flake lock file updates:
• Updated input 'CHaP':
'github:input-output-hk/cardano-haskell-packages/550ea1a' (2025-05-16)
→ 'github:input-output-hk/cardano-haskell-packages/68f4a94' (2025-12-11)
• Updated input 'hackage-nix':
'github:input-output-hk/hackage.nix/d1a38eb' (2025-10-01)
→ 'github:input-output-hk/hackage.nix/eb32a70' (2025-12-14)