[TRI-5377] bug: [v4] Middleware/lifecycle hooks defined in the `init.ts` file aren't picked up for deployed tasks

[matt-aitken]

• Define middleware like tasks.onStartup inside an init.ts file, which sits at the root of my trigger folder.
• In the development environment, everything works fine, I see logs like onStartup() and "Initializing Sentry", so I know the middleware is running.
• But in staging, none of those logs appear. It seems like the middleware isn't running at all.

Is there something different about how staging is handling the init file or middleware registration.

_TRI-5377