pkgs/cli: Add tagging support to machines list

Add the `--tags` flag to `clan machines list`
This now supports the machine tagging system from the inventory.

Multiple tags are the intersection of the tags of a specific machine.

Example two machines with overlapping tags:
```
server: ["intel"]
laptop: ["intel", "graphical"]
```

- `clan machines list --tags intel` will output:

```
server
laptop
```

- `clan machines list --tags intel graphical` will output:

```
laptop
```

- `clan machines list --tags graphical` will output:

```
laptop
```

pkgs/clan-cli/clan_cli/machines/list.py

@@ -10,6 +10,7 @@ from clan_cli.cmd import run_no_stdout
 from clan_cli.errors import ClanCmdError, ClanError
 from clan_cli.inventory import Machine, load_inventory_eval, set_inventory
 from clan_cli.nix import nix_eval, nix_shell
+from clan_cli.tags import list_nixos_machines_by_tags
 
 log = logging.getLogger(__name__)
 
@@ -132,9 +133,18 @@ def check_machine_online(
 
 def list_command(args: argparse.Namespace) -> None:
     flake_path = args.flake.path
+    if args.tags:
+        list_nixos_machines_by_tags(flake_path, args.tags)
+        return
     for name in list_nixos_machines(flake_path):
         print(name)
 
 
 def register_list_parser(parser: argparse.ArgumentParser) -> None:
+    tag_parser = parser.add_argument(
+        "--tags",
+        nargs="+",
+        default=[],
+        help="Tags that machines should be queried for. Multiple tags will intersect.",
+    )
     parser.set_defaults(func=list_command)