Mark smart-answers as using the default buildProject script
Mark smart-answers as using the default buildProject script

We changed smart-answers to use the default buildProject jenkins
script (see [smart-answers#3260](alphagov/smart-answers#3260) and so
our jenkins job no longer needs to explicitly wait on it before
reporting back to github.

alphagov/govuk-content-schemas,alphagov/govuk-content-schemas