Previously, the `deploy()` function in `deploy-to-firebase.js` would
also perform other operations (beyond deploying), such as building the
app, checking the generated payload size, testing the PWA score of the
deployed app.
This commit decouples these operations, so that deploying can be
performed independently.
NOTE:
In a subsequent commit, this will be leveraged fix an issue with
`rc.angular.io` redirects in the presence of a ServiceWorker by
deploying the same artifacts to multiple Firebase projects/sites.
See #39760 for more details.
PR Close#39853