Previously, we were running the e2e tests from master against
`https://angular.io` (deployed from the stable branch). Often the e2e
tests from master do not apply to the stable branch, since the app has
deviated slightly.
This commit fixes this by stop running the full e2e tests against the
deployed versions, but a smaller set of "smoke tests", which check basic
functionality that is less likely to change between versions.
PR Close#23390
George Kalpakas