* .drone.yml: Update file after updates to .drone.jsonnet
* .drone.jsonnet: Relocate guix_pipeline, guix_step, and deployStep to .drone/ci.libsonnet
library. Adjust existing function names to match new names in library.
Explicitly pass PLAN environment variable to ci.awsDeployStep for plan and apply stages
Adding the root user to /etc/passwd was only required when attempting to run guix shell
`-C|--container' commands, however guix shell containers will not work without privileged
docker, so when running via ci, we depend on the provided minimal guix container (build with
guix via 'guix pack -f docker ...').
* .drone.yml: This is now a generated file, based on .drone.jsonnet
* .drone.jsonnet: Add jsonnet drone pipeline configuration to replace existing .drone.yml
file. Note, currently this is used to manually generate .drone.yml. I need to determine how
to handle jsonnet libraries effectively as drone's built in jsonnet support does not allow
for importing libraries. In addition to converting to jsonnet, the pipeline was enhanced with
promotion and deployment functionality that has not yet been tested.
