This requires a lot of restructuring. The .nix files have to be bundled
together with the python files, so they need to follow python's module
system structure.
I ran `nix-fast-build --no-link -j 2 --eval-workers 3 --flake .#checks`
and it succeeded, so I'm reasonably confident I changed everything as
required.
154: tests: adjust wait_for_text calls to work for systemd-initrd or old stage-1 r=Mic92 a=lilyinstarlight
Co-authored-by: Lily Foster <lily@lily.flowers>