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/23d72dabcb3b12469f57b37170fcbc1789bd7457' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/078d69f03934859a181e81ba987c2bb033eebfc5?narHash=sha256-9yA/LIuAVQq0lXelrZPjLuLVuZdm03p8tfmHhnDIkms%3D' (2026-01-22)
  → 'github:NixOS/nixpkgs/23d72dabcb3b12469f57b37170fcbc1789bd7457?narHash=sha256-z5NJPSBwsLf/OfD8WTmh79tlSU8XgIbwmk6qB1/TFzY%3D' (2026-02-07)

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/042904167604c681a090c07eb6967b4dd4dae88c' into the Git cache...
unpacking 'github:pyproject-nix/pyproject.nix/b0d513eeeebed6d45b4f2e874f9afba2021f7812' into the Git cache...
unpacking 'github:pyproject-nix/uv2nix/5b43a934e15b23bfba6c408cba1c570eccf80080' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/private/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/078d69f03934859a181e81ba987c2bb033eebfc5?narHash=sha256-9yA/LIuAVQq0lXelrZPjLuLVuZdm03p8tfmHhnDIkms%3D' (2026-01-22)
  → 'github:NixOS/nixpkgs/23d72dabcb3b12469f57b37170fcbc1789bd7457?narHash=sha256-z5NJPSBwsLf/OfD8WTmh79tlSU8XgIbwmk6qB1/TFzY%3D' (2026-02-07)
• Updated input 'pyproject-nix':
    'github:pyproject-nix/pyproject.nix/ab521eddafb936498f18c86d83e1774a53b1cb8a?narHash=sha256-M%2BetHAj3oI9zr%2BCpj5u2kMAddvxcJCmnWRtH/SklYlY%3D' (2026-01-22)
  → 'github:pyproject-nix/pyproject.nix/b0d513eeeebed6d45b4f2e874f9afba2021f7812?narHash=sha256-kwCOegKLZJM9v/e/7cqwg1p/YjjTAukKPqmxKnAZRgA%3D' (2026-02-01)
• Updated input 'uv2nix':
    'github:pyproject-nix/uv2nix/9eeb39b8fdd8352bfc6f1af7eab79f88bd0a6eb3?narHash=sha256-6U2AQNC1Sa%2Bd7gUDQ58sqF39YVi5AKT9uHZSr%2BWVWGo%3D' (2026-01-22)
  → 'github:pyproject-nix/uv2nix/5b43a934e15b23bfba6c408cba1c570eccf80080?narHash=sha256-jlOvO%2B%2Buvne/lTgWqdI4VhTV5OpVWi70ZDVBlT6vGSs%3D' (2026-02-05)