Backports Zstandard (zstd)

backports-zstd is a library that backports the `compression.zstd` module, introduced in Python 3.14, to older Python versions (3.9 to 3.13). It provides a Pythonic interface for Zstandard compression, aiming to be as close as possible to the standard library's implementation. The library is currently at version 1.3.0 and is actively maintained, though it is designed to be superseded by the standard library module in Python 3.14 and later.