Revert "Merge pull request 'Make state-version generation an clan option' (#4056) from state-version-option into main"

This reverts commit 8a7b6d13b5, reversing
changes made to 7a4eeb5b16.

clanModules/flake-module.nix

@@ -33,6 +33,7 @@ in
     root-password = ./root-password;
     single-disk = ./single-disk;
     sshd = ./sshd;
+    state-version = ./state-version;
     static-hosts = ./static-hosts;
     sunshine = ./sunshine;
     syncthing = ./syncthing;

clanModules/state-version/README.md

@@ -0,0 +1,18 @@
+---
+description = "Automatically generate the state version of the nixos installation."
+features = [ "inventory", "deprecated" ]
+---
+
+This module generates the `system.stateVersion` of the nixos installation automatically.
+
+Options: [system.stateVersion](https://search.nixos.org/options?channel=unstable&show=system.stateVersion&from=0&size=50&sort=relevance&type=packages&query=stateVersion)
+
+Migration:
+If you are already setting `system.stateVersion`, then import the module and then either let the automatic generation happen, or trigger the generation manually for the machine. The module will take the specified version, if one is already supplied through the config.
+To manually generate the version for a specified machine run:
+
+```
+clan vars generate [MACHINE]
+```
+
+If the setting was already set you can then remove `system.stateVersion` from your machine configuration. For new machines, just import the module.

clanModules/state-version/default.nix

@@ -0,0 +1,6 @@
+# Dont import this file
+# It is only here for backwards compatibility.
+# Dont author new modules with this file.
+{
+  imports = [ ./roles/default.nix ];
+}

clanModules/state-version/roles/default.nix

@@ -0,0 +1,25 @@
+{ config, lib, ... }:
+let
+  var = config.clan.core.vars.generators.state-version.files.version or { };
+in
+{
+
+  warnings = [
+    "The clan.state-version module is deprecated and will be removed on 2025-07-15.
+      Please migrate to user-maintained configuration or the new equivalent clan services
+      (https://docs.clan.lol/reference/clanServices)."
+  ];
+
+  system.stateVersion = lib.mkDefault (lib.removeSuffix "\n" var.value);
+
+  clan.core.vars.generators.state-version = {
+    files.version = {
+      secret = false;
+      value = lib.mkDefault config.system.nixos.release;
+    };
+    runtimeInputs = [ ];
+    script = ''
+      echo -n ${config.system.stateVersion} > "$out"/version
+    '';
+  };
+}