min-copy-clocure test: ensure sshd up before starting

this test goes wrong intermittently in CI, see if this makes it more
reliable

tests/min-copy-closure/test.nix

@@ -25,6 +25,7 @@ pkgs.runCommand "check"
     mkdir vm
     ${img}/run.sh --lan user,hostfwd=tcp::2022-:22  --background ./vm
     expect ${./wait-until-ready.expect}
+    echo ready to go
     export SSH_COMMAND="ssh -o StrictHostKeyChecking=no -p 2022 -i ${./id}"
     $SSH_COMMAND root@localhost echo ready
     IN_NIX_BUILD=true min-copy-closure --quiet root@localhost ${rogue}