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/09eb77e94fa25202af8f3e81ddc7353d9970ac1b' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/c97c47f2bac4fa59e2cbdeba289686ae615f8ed4?narHash=sha256-OtzF5wBvO0jgW1WW1rQU9cMGx7zuvkF7CAVJ1ypzkxA%3D' (2025-12-04)
  → 'github:NixOS/nixpkgs/09eb77e94fa25202af8f3e81ddc7353d9970ac1b?narHash=sha256-mSD5Ob7a%2BT2RNjvPvOA1dkJHGVrNVl8ZOrAwBjKBDQo%3D' (2025-12-09)

warning: Git tree '/home/runner/work/lowrisc-nix/lowrisc-nix' is dirty
unpacking 'github:NixOS/nixpkgs/d2b1213bf5ec5e62d96b003ab4b5cbc42abfc0d0' into the Git cache...
unpacking 'github:pyproject-nix/build-system-pkgs/042904167604c681a090c07eb6967b4dd4dae88c' into the Git cache...
unpacking 'github:pyproject-nix/pyproject.nix/2c8df1383b32e5443c921f61224b198a2282a657' into the Git cache...
unpacking 'github:pyproject-nix/uv2nix/4cca323a547a1aaa9b94929c4901bed5343eafe8' into the Git cache...
warning: updating lock file "/home/runner/work/lowrisc-nix/lowrisc-nix/private/flake.lock":
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/c97c47f2bac4fa59e2cbdeba289686ae615f8ed4?narHash=sha256-OtzF5wBvO0jgW1WW1rQU9cMGx7zuvkF7CAVJ1ypzkxA%3D' (2025-12-04)
  → 'github:NixOS/nixpkgs/09eb77e94fa25202af8f3e81ddc7353d9970ac1b?narHash=sha256-mSD5Ob7a%2BT2RNjvPvOA1dkJHGVrNVl8ZOrAwBjKBDQo%3D' (2025-12-09)
• Updated input 'nixpkgs-2505':
    'github:NixOS/nixpkgs/ff06bd3398fb1bea6c937039ece7e7c8aa396ebf?narHash=sha256-8jemYbbW9EBttQKHep7Rj8kzXaxsrk/lACdXA2DN5Xk%3D' (2025-12-04)
  → 'github:NixOS/nixpkgs/d2b1213bf5ec5e62d96b003ab4b5cbc42abfc0d0?narHash=sha256-3C3xWn8/2Zzr7sxVBmpc1H1QfxjNfta5IMFe3O9ZEPw%3D' (2025-12-10)
• Updated input 'uv2nix':
    'github:pyproject-nix/uv2nix/1610e554e579c3d47b47c8a32d47042116d0e153?narHash=sha256-qBbyM1Gnvs/ncbnWfbBboMyevelz%2BowIdSN5Sg89wzw%3D' (2025-12-06)
  → 'github:pyproject-nix/uv2nix/4cca323a547a1aaa9b94929c4901bed5343eafe8?narHash=sha256-90d//IZ4GXipNsngO4sb2SAPbIC/a2P%2BIAdAWOwpcOM%3D' (2025-12-13)

[machshev]

Updated flake lock since this PR.