version up: zc.buildout, slapos.recipe.build, Debian 10/11 netinst
Thanks to the new buildout/slapos.recipe.build feature, we can download the last released version of Debian Stable. NEO stress testing is changed to run on both Debian 10 & 11. Keep proposing Debian 10 netinst in kvm SR, waiting that Debian 11 is more tested.