bug(example/slack-clone): Authlistner is not defined

# Bug report I made a pr without creating issue first , seems it got unoticed. It seems this is still relevant <!-- ⚠️ We receive a lot of bug reports which have already been solved or discussed. If you are looking for help, please try these first: - Docs: https://docs.supabase.com - Discussions: https://github.com/supabase/supabase/discussions - Discord: https://discord.supabase.com Before opening a bug report, please verify the following: --> - [x] I confirm this is a bug with Supabase, not with my own application. - [x] I confirm I have searched the [Docs](https://docs.supabase.com), GitHub [Discussions](https://github.com/supabase/supabase/discussions), and [Discord](https://discord.supabase.com). ## Describe the bug Running slack-clone example causes authlistner not defined error. ## To Reproduce 1. go to `examples/slack-clone/nextjs-slack-clone` folder 2. `npm install` 3. `npm run dev` ## Expected behavior A clear and concise description of what you expected to happen. ## Screenshots <img width="1051" height="535" alt="Screenshot from 2025-12-13 14-51-29" src="https://github.com/user-attachments/assets/772d292f-1356-4ede-ba2a-eef0b569a583" /> ## System information node: v23.0.0 npm : 10.9.0 ubuntu: 24.04.03 - OS: [e.g. macOS, Windows] - Browser (if applies) [e.g. chrome, safari] - Version of supabase-js: [e.g. 6.0.2] - Version of Node.js: [e.g. 10.10.0] ## Additional context Add any other context about the problem here.