[NEW PORT] devel/py-maturin

[kai]

Summary

Build and publish crates with pyo3, rust-cpython and cffi bindings as well
as Rust binaries as Python packages.

This project is meant as a zero configuration replacement for
setuptools-rust and milksnake.  It supports building wheels for Python 3.5+
on FreeBSD and various other platforms, can upload them to PyPI and has
basic PyPy support.

WWW: https://github.com/PyO3/maturin

PR: 247666

Test Plan

• poudriere -> OK (11.4-, 12.1-RELEASE, 13.0-CURRENT@r366935 [amd64 only] with py36, py37, py38 and py39)

[kai]

• Remove superfluous ${ECHO_CMD} from post-install target.

[tcberner]