roles/archbuild: Use a more generic sudoers rule

Rather than explicitly listing each command allowed, match any
executable of the form /usr/bin/*-x86_64-build -- this will only ever be
a symlink to archbuild which is all we are looking for.

devtools allows new archbuild configurations to be easily added by
creating a symlink of the form ${config}-${arch}-build and adding the
relevant /usr/share/devtools/pacman-${config}.conf

This change allows the sudoers policy to automatically support these, in
the event that devtools distributes new archbuild configs or a sysadmin
adds a custom one.

roles/archbuild/files/sudoers

 Cmnd_Alias ARCHBUILD = /usr/sbin/makechrootpkg, /usr/sbin/mkarchroot, \
-                       /usr/bin/extra-i686-build,          /usr/bin/extra-x86_64-build, \
-                       /usr/bin/testing-i686-build,        /usr/bin/testing-x86_64-build, \
-                       /usr/bin/staging-i686-build,        /usr/bin/staging-x86_64-build, \
-                       /usr/bin/kde-unstable-i686-build,   /usr/bin/kde-unstable-x86_64-build, \
-                       /usr/bin/gnome-unstable-i686-build, /usr/bin/gnome-unstable-x86_64-build, \
+                       /usr/bin/*-i686-build,          /usr/bin/*-x86_64-build, \
                        /usr/sbin/arch-nspawn, /usr/local/bin/syncrepo, /usr/bin/multilib-build, \
                        /usr/bin/multilib-testing-build,    /usr/bin/multilib-staging-build