Install netcat-openbsd in tests

In Ubuntu 22.04 `netcat` was an alias for `netcat-openbsd`. This isn't present in 22.04 which base-notebook was recently upgraded to.

.github/workflows/test.yaml

@@ -66,7 +66,7 @@ jobs:
           echo "::group::Install netcat, a test dependency"
           docker exec --user root $container_id bash -c '
               apt update
-              apt install -y netcat
+              apt install -y netcat-openbsd
           '
           echo "::endgroup::"