debootsnap: skip cleanup/reproducible to keep the dbus/machine-id

debootsnap calls mmdebstrap to create a chroot and that cleans up some non reproducible files by default. This make the chroot different to one generated by sbuild and let packages that use dbus in their tests fail to reproduce with debrebuild. The effected packages where:

golang-dbus golang-github-crowdsecurity-machineid python-pystray-doc ibus python-sdbus glib2.0