-`boot.enableContainers` is only turned on when a declarative NixOS container is defined in `containers`.
If you use the `nixos-container` tool for imperative container management, set `boot.enableContainers = true;` explicitly.
-`etcd` package was upgraded to 3.6, see [migration notes](https://etcd.io/docs/v3.6/upgrades/upgrade_3_6/) for incompatibilities and upgrade procedure.
-`services.parsoid` and the `nodePackages.parsoid` package have been removed, as the JavaScript-based version this module uses is not compatible with modern MediaWiki versions.
-`virtualisation.lxd` has been removed due to lack of Nixpkgs maintenance. Users can migrate to `virtualisation.incus`, a fork of LXD, as a replacement. See [Incus migration documentation](https://linuxcontainers.org/incus/docs/main/howto/server_migrate_lxd/) for migration information.