Setup integration tests for process.js

[joyeecheung]

Locally, I have been doing this to run integration tests:

node --env-file actions/.env.bsky actions/test/integration.js

(as documented in the automation.md, too)

Which just copies the actions in https://github.com/nodejs/bluesky/tree/main/actions/test/examples/new to a temporary directy and run process.js on them to a live account https://bsky.app/profile/pixel-voyager.bsky.social

It would be nice to set up a test account (I don't mind donating pixel-voyager, but it's linked to a personal email and it feels weird) and some workflows that does this when the automation scripts are updated, to help verifying they are good. Ideally the workflows should be manually triggered to avoid getting rate-limited by Bluesky (not super likely since it's pretty relaxed in terms of limits, but it's good to avoid wasting resources on the planet).