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_modules.py

@@ -13,7 +13,7 @@ from clan_cli.nix import nix_eval, run_no_stdout
 if TYPE_CHECKING:
     from age_keys import KeyPair
 
-from cli import Cli
+from helpers.cli import Cli
 
 from clan_cli.machines.facts import machine_get_fact