Clean up PUDL build script cruft

[zaneselvans]

Overview

I think there are some derelict bits in our nightly build setup that should be cleaned up:

Tasks

Beta Give feedback

1. Get rid of obsolete (?) pudl-deployment-tag and pudl-deployment-dev VMs in GCP
2. Remove all references to GCE_INSTANCE / `GCE_INSTANCE_ZONE in the build workflow / script
3. Update docs on how to ssh into a running instance to reflect our use of Google Batch
4. Update docs on how to debug a failed build to reflect our use of Google Batch