flake.lock: Update

[github-actions]

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

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/406a04b6598830565037b8571bd317db718e38d1?narHash=sha256-0fF2663lf47Xv1P7tPfIQEtNa/ItI0K1ALeCks1LbR4%3D' (2025-01-19)
  → 'github:nixos/nixpkgs/76802278cafb68debdf9020c913accbb4d3bbc64?narHash=sha256-mhdnw6zrtMImJ06qT5M2LpxtUemFY4flOQxYDdDEh44%3D' (2025-01-26)

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