chore(deps): Update flake.lock

[spoon-bot]

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

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/b85ed9dcbf187b909ef7964774f8847d554fab3b' (2023-08-22)
  → 'github:NixOS/nixpkgs/aa8aa7e2ea35ce655297e8322dc82bf77a31d04b' (2023-09-01)

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