Getting `AttributeError: 'PathsWrapper' object has no attribute '_path' `

Code from running: https://bbpgitlab.epfl.ch/molsys/bbp_me_type_to_mol_id/-/blob/main/downloader/BBP_downloader.py is causing the following exception:

```
Enter NEXUS token
seaching morphologies...
Traceback (most recent call last):
File "BBP_downloader.py", line 23, in
path.annotation.hasBody.type == "MType",
File "/home/gevaert/src/nexus-forge/kgforge/core/wrappings/paths.py", line 70, in __eq__
return self._for(FilterOperator.EQUAL.value, other)
File "/home/gevaert/src/nexus-forge/kgforge/core/wrappings/paths.py", line 82, in _for
return Filter(self._path, operator, other)
AttributeError: 'PathsWrapper' object has no attribute '_path'
```

I believe it's because the `__dict__` is being reset here:
https://github.com/BlueBrain/nexus-forge/blob/master/kgforge/core/wrappings/paths.py#L94