Update flake.lock

[github-actions]

Automated changes by the update-flake-lock GitHub Action.

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/ecd26a469ac56357fd333946a99086e992452b6a?narHash=sha256-ET91TMkab3PmOZnqiJQYOtSGvSTvGeHoegAv4zcTefM%3D' (2025-01-24)
  → 'github:NixOS/nixpkgs/9189ac18287c599860e878e905da550aa6dec1cd?narHash=sha256-AYvaFBzt8dU0fcSK2jKD0Vg23K2eIRxfsVXIPCW9a0E%3D' (2025-01-31)

Running GitHub Actions on this PR

GitHub Actions will not run workflows on pull requests which are opened by a GitHub Action.

To run GitHub Actions workflows on this PR, run:

git branch -D update_flake_lock_action
git fetch origin
git checkout update_flake_lock_action
git commit --amend --no-edit
git push origin update_flake_lock_action --force