This change does two things:
- It ensures that as part of publishing the SDK, we also publish an
updated pulumi/pulumi docker image (tagged with both `latest` and
`vX.Y.Z`
- Makes this image published by this repository less perscriptive in a
workflow. The instead of having wrapper scripts that try to invoke
Pulumi based on conventions. It is now just a base image that has
the pulumi CLI installed, as well as the SDKs for the major cloud
providers. We'll use this base layer in our github actions image,
which will layer on a github actions centric workflow
Fixes#1991
389a3721ec