clean it up after copying the tarballs
i really hate how this logic is written, it's clunky
but it should work; the only issue is that it's quite
slow, and inefficient on use of disk space.
however, i've not yet figured out how to reproducible
add files to a tarball, once the tarball has been created,
and i rely on sorting (of file names) when creating them.
it's really not a problem because normal people won't
use this script, only i or anyone who wants to test out
the libreboot release infrastructure. this script is
largely intended to *work*
but i'm still annoyed by how crappy it is. i'll fix it
after the Libreboot 20231021 release.
Signed-off-by: Leah Rowe <leah@libreboot.org>