flake.lock: Update

[github-actions]

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

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/52ec9ac3b12395ad677e8b62106f0b98c1f8569d?narHash=sha256-veKR07psFoJjINLC8RK4DiLniGGMgF3QMlS4tb74S6k%3D' (2024-07-28)
  → 'github:NixOS/nixpkgs/71e91c409d1e654808b2621f28a327acfdad8dc2?narHash=sha256-GnR7/ibgIH1vhoy8cYdmXE6iyZqKqFxQSVkFgosBh6w%3D' (2024-08-28)

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