flake.lock: Update

[github-actions]

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

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/103a4c0ae46afa9cf008c30744175315ca38e9f9' (2022-06-17)
  → 'github:NixOS/nixpkgs/e0a42267f73ea52adc061a64650fddc59906fc99' (2022-06-18)

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