Release-please should be a separate job in release workflows #56
Description
Having release-please and subsequent publish actions (npm, dockerhub, etc) in the same job makes it basically impossible to rerun the failed publish steps after, say, refreshing a token or updating an npm config. A rerun of release-please sees the release already made on GitHub and quits without moving on to the other parts.
This simpler structure is used in the release workflows of several shaka-project repos, and needs to be split up for resilience.