chore: nix flake update

[lowrisc-ci]

Automated update to nix flake inputs

Logs:

warning: ignoring untrusted flake configuration setting 'extra-substituters'.
Pass '--accept-flake-config' to trust it
warning: ignoring untrusted flake configuration setting 'extra-trusted-public-keys'.
Pass '--accept-flake-config' to trust it
unpacking 'github:numtide/flake-utils/11707dc2f618dd54ca8739b309ec4fc024de578b' into the Git cache...
unpacking 'github:NixOS/nixpkgs/25f538306313eae3927264466c70d7001dcea1df' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/755f5aa91337890c432639c60b6064bb7fe67769?narHash=sha256-ypxFOeDz%2BCqADEQNL72haqGjvZQdBR5Vc7pyx2JDttI%3D' (2026-04-29)
  → 'github:NixOS/nixpkgs/25f538306313eae3927264466c70d7001dcea1df?narHash=sha256-ZsIrKmhp4vbBXoXXmR/tBXA/UCsAQiJL9vsgZEduhVY%3D' (2026-05-26)

warning: Git tree '/home/runner/work/lowrisc-nix/lowrisc-nix' is dirty
unpacking 'github:NixOS/nixpkgs/ac62194c3917d5f474c1a844b6fd6da2db95077d' into the Git cache...
unpacking 'github:pyproject-nix/build-system-pkgs/7bff980f37fc24e09dbc986643719900c139bf12' into the Git cache...
unpacking 'github:pyproject-nix/pyproject.nix/a228447c3e179d477c1b6246ef3efa8cfe3c469a' into the Git cache...
unpacking 'github:pyproject-nix/uv2nix/fdf2a76275d7a9c27deb5d2f2ab33526ac9052ff' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/private/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/755f5aa91337890c432639c60b6064bb7fe67769?narHash=sha256-ypxFOeDz%2BCqADEQNL72haqGjvZQdBR5Vc7pyx2JDttI%3D' (2026-04-29)
  → 'github:NixOS/nixpkgs/25f538306313eae3927264466c70d7001dcea1df?narHash=sha256-ZsIrKmhp4vbBXoXXmR/tBXA/UCsAQiJL9vsgZEduhVY%3D' (2026-05-26)
• Updated input 'pyproject-build-systems':
    'github:pyproject-nix/build-system-pkgs/ffaa2161dd5d63e0e94591f86b54fc239660fb2e?narHash=sha256-qapCOQmR%2B%2ByZSY43dzrp3wCrkOTLpod%2BONtJWBk6iKU%3D' (2026-04-20)
  → 'github:pyproject-nix/build-system-pkgs/7bff980f37fc24e09dbc986643719900c139bf12?narHash=sha256-MbXylBTkWqVm8/VYjoULtMoVRgWBN1gSHbeRKsOsPlU%3D' (2026-05-25)
• Updated input 'pyproject-nix':
    'github:pyproject-nix/pyproject.nix/69f57f27e52a87c54e28138a75ec741cd46663c9?narHash=sha256-Gs1VnEkCkkRZxJQAC/Dhz0Jbfi22mFXChbtNg9w/Ybg%3D' (2026-04-20)
  → 'github:pyproject-nix/pyproject.nix/a228447c3e179d477c1b6246ef3efa8cfe3c469a?narHash=sha256-GSKXTAnFqRAMlZkJrIPcQMYf%2BlpMr66K3i60mB9STvc%3D' (2026-05-16)
• Updated input 'uv2nix':
    'github:pyproject-nix/uv2nix/6c53dcf4d3f63240f57e0b0c826cb15eda61f249?narHash=sha256-1PcD0%2BIZPQXyvmXJ1OYH%2B23sRc9IyOKrUUBYZonVBm8%3D' (2026-04-29)
  → 'github:pyproject-nix/uv2nix/fdf2a76275d7a9c27deb5d2f2ab33526ac9052ff?narHash=sha256-IMFlxeyClau51KplhhSRGhdGTvD/knShHdybP1UOTuk%3D' (2026-05-22)