This PR adds a basic deployment test to the repository. This test will, in a NixOS test, run a deployer VM and a target VM, and check that we manage to run `nixops4 apply` on the deployer VM to change things on the target VM. The ideas are all @roberth's and this test has been extremely heavily inspired by https://github.com/nixops4/nixops4-nixos/blob/main/test/default/nixosTest.nix.
Reviewed-on: Fediversity/Fediversity#323
Reviewed-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-authored-by: Nicolas “Niols” Jeannerod <nicolas.jeannerod@moduscreate.com>
Co-committed-by: Nicolas “Niols” Jeannerod <nicolas.jeannerod@moduscreate.com>