rust-cpython: removed now useless py_set() conversion...
rust-cpython: removed now useless py_set() conversion
In rust-cpython 0.3.0, HashSets implement the appropriate
ToPythonObject, we can therefore get rid of this hacky conversion.
There still remains an inefficiency in `MissingAncestors.bases()`:
we have to clone, because `to_py_object()` requires full ownership.
However:
- the only use case outside of unit tests used to be from
`setdiscovery.partialdiscovery` which is now fully implemented
in Rust.
- it's not worse than what `py_set()` used to do
Differential Revision:
https://phab.mercurial-scm.org/D7120
