flake.lock: Update

Flake lock file updates:

• Updated input 'flake-parts':
    'github:hercules-ci/flake-parts/4524271976b625a4a605beefd893f270620fd751?narHash=sha256-%2BuWLQZccFHwqpGqr2Yt5VsW/PbeJVTn9Dk6SHWhNRPw%3D' (2025-09-01)
  → 'github:hercules-ci/flake-parts/f7c1a2d347e4c52d5fb8d10cb4d94b5884e546fb?narHash=sha256-m1Yf0wZ8j1OHjTc2UwHwyQRSnNeSgLJOd7q5Y45hzi4%3D' (2026-05-13)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/8eb28adfa3dc4de28e792e3bf49fcf9007ca8ac9?narHash=sha256-NOrUtIhTkIIumj1E/Rsv1J37Yi3xGStISEo8tZm3KW4%3D' (2025-09-05)
  → 'github:NixOS/nixpkgs/a799d3e3886da994fa307f817a6bc705ae538eeb?narHash=sha256-3av0pIjlOWQ6rDbNOmpUSvbNnJkGORQKKjb4LtCZsIY%3D' (2026-06-06)
• Updated input 'treefmt-nix':
    'github:numtide/treefmt-nix/5eda4ee8121f97b218f7cc73f5172098d458f1d1?narHash=sha256-ySNJ008muQAds2JemiyrWYbwbG%2BV7S5wg3ZVKGHSFu8%3D' (2025-09-24)
  → 'github:numtide/treefmt-nix/db947814a175b7ca6ded66e21383d938df01c227?narHash=sha256-eynAfOmbmxJnkp7YewvCEbShNnnYJ9gLLqkzsYtBPeM%3D' (2026-05-31)

Author: github-actions[bot]