Set up slack notifications for failing AI e2e tests

[Irev-Dev]

The ML team wants notifications in slack for when there are failures in

e2e/playwright/prompt-to-edit.spec.ts
e2e/playwright/text-to-cad-tests.spec.ts

They run early enough that it can help indicate a problem with their endpoint.

See these slack threads too:
https://kittycadworkspace.slack.com/archives/C030D6PR135/p1741645854199789
https://kittycadworkspace.slack.com/archives/C04KFV6NKL0/p1741381658820369

[Irev-Dev]

CC @greg-kcio

[greg-kcio]

Thank you! You can send them to #ml-notifications

[jtran]

I know this is expanding scope, and any notifications are better than none. But whenever you make something that notifies on failure, you basically want to record the heartbeat on success. And then have another monitor that notifies you if there hasn't been a successful heartbeat in a while. It's a common pattern for infrastructure.

Always remember: who watches the watcher? 🙂