When this command is run on CI, `yarn build` has already been run, so
this was unnecessarily building angular.io again (adding ~4mins to the
`aio` job).
When this command is run locally, it is most often about testing a new
`lighthouse` version/config, so you don't need to build angular.io over
and over (and if necessary, one can always run `yarn build` manually).
Closes#19633