Shipout packages local repo instead of using git

Shipout should use `git` to download the repository to the server, then utilize the normal node pipeline (possibly with the added step of installing `volta`) in order that we don't have to zip and deploy all of our `node_modules` with a particular bundle.

No files or tests are named. Start by tracing how Shipout currently packages and deploys a Node application, then compare that flow with downloading the repository through git and running the normal Node pipeline, optionally installing Volta; done means deployments no longer require bundling node_modules.

Written by the indexing model from the issue text.