Generic single-database configuration.

See https://github.com/tiangolo/full-stack-fastapi-postgresql/blob/d91ed067a83953dca20783c17cd69394e62726b4/src/backend/app/alembic/env.py

This is here instead of the project root because poetry refuses to bee able to package
non-python files from different places:
- https://github.com/Qonfused/OCE-Build/issues/12
- https://github.com/python-poetry/poetry/issues/890