Remove id(1)

Remove id(1)

Distributions use id(1) from GNU coreutils or BusyBox.  Drop ours.

Closes: <https://github.com/shadow-maint/shadow/issues/1005>
Suggested-by: dkwo <nicolopiazzalunga@gmail.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Michael Vetter <jubalh@iodoru.org>
Cc: Sam James <sam@gentoo.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>