[GHF] Report workflow startup failures (#81521)
Because they are not reported in signal box and as such very easy to
miss, see https://github.com/pytorch/pytorch/pull/81044 for example
TODO: Figure out how hard it it to adapt [actionlint](https://github.com/rhysd/actionlint) to validate composite workflows
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81521
Approved by: https://github.com/kit1980, https://github.com/clee2000
