lightning run cli entry point stopped working after dropping app from top level

[awaelchli]

Bug description

After #18386, the lightning cli entry point (e.g. lightning run model ...) exists but no longer works due to missing dependencies.

What version are you seeing the problem on?

master

How to reproduce the bug

pip install lightning
lightning run --help

Error messages and logs

Traceback (most recent call last):
  File "/Users/adrian/miniconda3/envs/lightning-fresh/bin/lightning", line 5, in <module>
    from lightning.app.cli.lightning_cli import main
  File "/Users/adrian/miniconda3/envs/lightning-fresh/lib/python3.11/site-packages/lightning/app/__init__.py", line 32, in <module>
    from lightning.app.core.app import LightningApp  # noqa: E402
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/adrian/miniconda3/envs/lightning-fresh/lib/python3.11/site-packages/lightning/app/core/__init__.py", line 1, in <module>
    from lightning.app.core.app import LightningApp
  File "/Users/adrian/miniconda3/envs/lightning-fresh/lib/python3.11/site-packages/lightning/app/core/app.py", line 25, in <module>
    from deepdiff import DeepDiff, Delta
ModuleNotFoundError: No module named 'deepdiff'

Environment

Lightning 2.1+ all platforms.

More info

No response

[shaibagon]

got it for 2.1.4