ac19ff2b

By: Michael Lynch <git@mtlynch.io>

Enforce external test packages in all Go test files

Add dev-scripts/check-go-test-packages, which verifies that every
tracked *_test.go file declares a package ending in _test.

Wire it into the pre-commit hook and add a corresponding Nix build step
in flake.nix.

Co-authored-by: Shelley <shelley@exe.dev>