Cast path to string

[CptCaptain]

In some cases this might be a PosixPath, causing issues downstream.

Fixes #618

[daavoo]

I am not sure in which scenarios this is failing, though.
Tried to add a test but self._dvc_repo.add(path) doesn't fail.

@CptCaptain Could you share your DVC version?

[CptCaptain]

Sure, I'm using these versions:

dvc==2.58.2
dvc-data==0.51.0
dvc-gs==2.22.1
dvc-http==2.30.2
dvc-objects==0.23.0
dvc-render==0.5.3
dvc-studio-client==0.11.0
dvc-task==0.3.0
dvclive==2.12.0

This all runs from the ultralytics repo, if that makes a difference.

[daavoo]

Ok, appears to be some issue that has been resolved in more recent DVC versions (in the latest version the error doesn't appear).

I am able to reproduce this when installing those pinned dependencies.

[skshetry]

This was fixed in dvc 3.0.