Uninstall failed to delete nixbld users

[edolstra]

After running the Determinate installer's uninstall, the _nixbld* users still existed. (This causes attempts to run the upstream installer to fail, see NixOS/nix#12343.)

For some reason, _nixbld* users are in an undeletable state:

ephemeraladmin@mac-epic-turducken ~ % sudo dscl . -rm /Users/_nixbld1  
<main> delete status: eDSPermissionError
<dscl_cmd> DS Error: -14120 (eDSPermissionError)

which may be why the uninstaller failed to get rid of them.

[cole-h]

We actually have a warning for this exact case:

nix-installer/src/action/base/create_user.rs

Line 383 in 9c5542a

tracing::warn!("Encountered an exit code 40 with -14120 error while removing user, this is likely because the initial executing user did not have a secure token, or that there was no graphical login session. To delete the user, log in graphically, then run `/usr/bin/dscl . -delete /Users/{}`", name);

I don't think there's anything we can really do to fix this, unfortunately.