refactor: moved nixos modules to dendrite pattern

modules/nixos/home-manager-adaptors/i18n.nix

@@ -0,0 +1,28 @@
+{...}: {
+  flake.nixosModules.home-manager-i18n = {
+    lib,
+    config,
+    ...
+  }: let
+    home-users = lib.attrsets.mapAttrsToList (_: user: user) config.home-manager.users;
+  in {
+    config = {
+      i18n.supportedLocales =
+        lib.unique
+        (builtins.map (l: (lib.replaceStrings ["utf8" "utf-8" "UTF8"] ["UTF-8" "UTF-8" "UTF-8"] l) + "/UTF-8") (
+          [
+            "C.UTF-8"
+            "en_US.UTF-8"
+            config.i18n.defaultLocale
+          ]
+          ++ (lib.attrValues (lib.filterAttrs (n: v: n != "LANGUAGE") config.i18n.extraLocaleSettings))
+          ++ (
+            map (user-config: user-config.i18n.defaultLocale) home-users
+          )
+          ++ (lib.lists.flatten (
+            map (user-config: lib.attrValues (lib.filterAttrs (n: v: n != "LANGUAGE") user-config.i18n.extraLocaleSettings)) home-users
+          ))
+        ));
+    };
+  };
+}