click: should _PathType allow pathlib.Path?

[remexre]

https://github.com/python/typeshed/blob/master/stubs/click/click/types.pyi#L73

https://github.com/pallets/click/blob/main/src/click/types.py#L767-L769

[JelleZijlstra]

The usage of the TypeVar dooesn't make a ton of sense to me since it's not in a generic class. Maybe it should instead use one of the aliases from _typeshed.

[Akuli]

We no longer have stubs for pallets projects (including click). #5423