optree v0.9.1

Patch Release [0.9.1] - 2023-05-23

Changed

• Use py::type::handle_of(obj) rather than deprecated obj.get_type() by @XuehaiPan in #49.
• Bump abseil-cpp version to 20230125.3 by @XuehaiPan in #57.

Fixed

• Add @runtime_checkable decorator for CustomTreeNode protocol class by @XuehaiPan in #56.

Full Changelog: v0.9.0...v0.9.1