Add dockerfile for performing an empty database build

[MoralCode]

Description
I recently created https://github.com/orgs/chaoss/packages/container/package/augur_empty_database, a GHCR container containing an empty augur Database for the purposes of enabling a downstream project like 8Knot to run CI jobs without needing to publish credentials to a publicly accessible database.

This container is a very thin wrapper around postgres 16 that ships postgres data for an empty augur db. While this intentionally violates usual docker conventions of storing postgres data in volumes, it does so to enable downstream projects to provide their CI jobs with SOMETHING to connect to in place of a real augur database for the purpose of testing.

This path was easier than attempts to create scripts that could anonymize an existing augur db for use in CI jobs.

This PR adds a dockerfile that can ensure this empty database image stays up to date as the augur schema evolves, as well as includes it in the existing docker build pipeline.

Notes for Reviewers
This dockerfile is largely a copy paste of the existing backend docker compose with some things removed (keyman, etc) that are not likely to be needed for the sole purpose of running augur db create-schema.

If theres a way to COPY this augur CLI binary and reduce the duplication in build steps with this container, that would also be super helpful.

Signed commits

• Yes, I signed my commits.

[sgoggins]

LGTM!