Set up slack notifications for daily E2E tests

[samsiegart]

From @ivanlei:

Ideally i’d like the daily CI runs to all go to [#ops-engineering](https://agoricopco.slack.com/archives/C038TEA5YTG) like https://agoricopco.slack.com/archives/C038TEA5YTG/p1712691273501559
But I’d want:
the slack messages to say more clearly I’m a (daily, weekly, <timeframe>) CI run of <link to thing>
ideally each failure to file a GH issue or :1+: an existing issue