Revert "remove nix_shell_legacy"

This reverts commit 8cde32c76f.

pkgs/clan-cli/clan_cli/api/directory.py

@@ -6,7 +6,7 @@ from typing import Any, Literal
 
 from clan_cli.cmd import RunOpts
 from clan_cli.errors import ClanError
-from clan_cli.nix import nix_shell, run_no_stdout
+from clan_cli.nix import nix_shell_legacy, run_no_stdout
 
 from . import API
 
@@ -126,8 +126,8 @@ def show_block_devices() -> Blockdevices:
     It must return a list of block devices.
     """
 
-    cmd = nix_shell(
-        ["util-linux"],
+    cmd = nix_shell_legacy(
+        ["nixpkgs#util-linux"],
         [
             "lsblk",
             "--json",

pkgs/clan-cli/clan_cli/api/mdns_discovery.py

@@ -3,7 +3,7 @@ import re
 from dataclasses import dataclass
 
 from clan_cli.cmd import run_no_stdout
-from clan_cli.nix import nix_shell
+from clan_cli.nix import nix_shell_legacy
 
 from . import API
 
@@ -89,8 +89,8 @@ def parse_avahi_output(output: str) -> DNSInfo:
 
 @API.register
 def show_mdns() -> DNSInfo:
-    cmd = nix_shell(
-        ["avahi"],
+    cmd = nix_shell_legacy(
+        ["nixpkgs#avahi"],
         [
             "avahi-browse",
             "--all",