clan-cli tests: remove dynamic inclusion of helpers module

Dynamically extending the python path at runtime is bad for developer experience, as this is not understood by the text editor and therefore jump to definition etc. does not work.

-> Better to remove the dynamic inclusion and force developers to specify the import correctly.

pkgs/clan-cli/tests/test_vms_cli.py

@@ -7,8 +7,8 @@ from time import sleep
 from typing import TYPE_CHECKING
 
 import pytest
-from cli import Cli
 from fixtures_flakes import FlakeForTest, generate_flake
+from helpers.cli import Cli
 from root import CLAN_CORE
 
 from clan_cli.dirs import vm_state_dir