notabug is unreliable, even as a backup.

why, just today, it was offline! all day.

i originally moved libreboot away from notabug,
to codeberg instead, but kept the notabug account
online, and i still push to it when it's online.

however, notabug seems to be in a terminal state
of neglect by its admins, so lbmk should not use it.

Signed-off-by: Leah Rowe <leah@libreboot.org>

it's downloaded by .gitmodules in stm32-vserprog

Signed-off-by: Leah Rowe <leah@libreboot.org>

don't put multiple downloads in the same files, except
when they are dependencies that go inside the directory
of another download.

by doing this, the following functionality will become
possible: clean every project or build every project,
or maybe fetch every project, based entirely on the
names of these files.

this will be used later to simplify the release script.

Signed-off-by: Leah Rowe <leah@libreboot.org>