Why drop this make target?

It's important for developers to be able to more-or-less exactly (closer the better) reproduce CI build/test locally so that we can reproduce errors that CI discovers. To that end, you want to keep all the logic in the Makefile or build scripts and then the CI just executes those targets/scripts.

This PR takes us in the opposite direction, removing stuff from make and baking it into the CI.

This assumes an external PostgreSQL instance is running, which breaks a pretty fundamental rule of make (which declares explicit chaining dependencies).

I'm fine to move this in a script, but it's not idiomatic to have a make target with external deps.

Fair. Would be nice to have a .PHONY target that runs a script to ensure the postgres docker container is up, and list it in the dependencies of this target.