flake: update inputs (#554)

Flake lock file updates:

• Updated input 'nixpkgs-stable':
    'github:NixOS/nixpkgs/4005c3ff7505313cbc21081776ad0ce5dfd7a3ce?narHash=sha256-VIAjBr1qGcEbmhLwQJD6TABppPMggzOvqFsqkDoMsAY%3D' (2024-12-25)
  → 'github:NixOS/nixpkgs/d49da4c08359e3c39c4e27c74ac7ac9b70085966?narHash=sha256-MgdXpeX2GuJbtlBrH9EdsUeWl/yXEubyvxM1G%2ByO4Ak%3D' (2024-12-27)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/e0b3654b716098b47f3643c65fbb75ef49c033e1?narHash=sha256-2XkWYGgT%2B911gOLjgBj%2B8W8ZJk6P0qHJNz8RfKgT/5o%3D' (2024-12-27)
  → 'github:oxalica/rust-overlay/a16b9a7cac7f4d39a84234d62e91890370c57d76?narHash=sha256-3zXufMRWUdwmp8/BTmxVW/k4MyqsPjLnnt/IlQyZvhc%3D' (2024-12-28)

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