Update example/flake.lock

[github-actions]

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

Flake lock file updates:

• Updated input 'haskell-flake':
    'github:srid/haskell-flake/8bffb2266b38fe7983d14fc4858aea2e64ad2175?narHash=sha256-h9cBnB1hfF73g/K7FJtsOdcE0mbi00qBGCJ%2BCFH7jRQ%3D' (2024-06-09)
  → 'github:srid/haskell-flake/3f76199d42d55e3a36bf8e8e0544e715d6a3f007?narHash=sha256-6CToXT/jcbYBi3EMAZZtyPj14NsMbdAwq%2BZeQtfu5P0%3D' (2024-06-20)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/3f84a279f1a6290ce154c5531378acc827836fbb?narHash=sha256-u1fA0DYQYdeG%2B5kDm1bOoGcHtX0rtC7qs2YA2N1X%2B%2BI%3D' (2024-06-13)
  → 'github:nixos/nixpkgs/90338afd6177fc683a04d934199d693708c85a3b?narHash=sha256-%2B1xgeIow4gJeiwo4ETvMRvWoircnvb0JOt7NS9kUhoM%3D' (2024-06-21)

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