exception in get_description in pypi for packagecode

### Description
Got this error while using pypi from packagecode
```
File "/home/tg1999/Desktop/python-inspector/src/_packagedcode/pypi.py", line 971, in get_description
description = get_legacy_description(location=fileutils.parent_directory(location))
File "/home/tg1999/Desktop/python-inspector/venv/lib/python3.8/site-packages/commoncode/fileutils.py", line 213, in parent_directory
left, _right = split_parent_resource(path, force_posix)
File "/home/tg1999/Desktop/python-inspector/venv/lib/python3.8/site-packages/commoncode/fileutils.py", line 187, in split_parent_resource
use_posix = force_posix or is_posixpath(path)
File "/home/tg1999/Desktop/python-inspector/venv/lib/python3.8/site-packages/commoncode/fileutils.py", line 148, in is_posixpath
has_slashes = '/' in location
TypeError: argument of type 'Path' is not iterable
```

### How To Reproduce
Path was `.cache/thirdparty/click_didyoumean-0.3.0-py3-none-any.whl/click_didyoumean-0.3.0.dist-info/METADATA`

### System configuration

* What OS are you running on? Linux
* What version of scancode-toolkit was used to generate the scan file?
* What installation method was used to install/run scancode? source download