Remove weston.bin pkg from gen3 machine conf

Remove weston.bin pkg from gen3 machine conf

 * weston.bin should be add only with pkg-group
   or image recipes.
 * No weston on m3ulcb-nogfx

Change-Id: Iaa62cbf3a07714a5c9dad014b72feb00927b1e71
Signed-off-by: Ronan Le Martret <ronan.lemartret@iot.bzh>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/10907
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Tested-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Stéphane Desneux <stephane.desneux@iot.bzh>