Add pyo3 0.15 rust packages
This is mostly the same from the existing pyo3 project, but packaged the older, still supported 0.15.2 version, because some projects, like the current release of python-cryptography 37.0, depend on that version.
This is mostly the same from the existing pyo3 project, but packaged the older, still supported 0.15.2 version, because some projects, like the current release of python-cryptography 37.0, depend on that version.