Warn about PEP 784: Zstandard in the standard library

[Pierre-Sassoulas]

Current problem

The new compression package contains modules compression.lzma, compression.bz2, compression.gzip and compression.zlib which re-export the lzma, bz2, gzip and zlib modules respectively. The new import names under compression are the canonical names for importing these compression modules going forward. However, the existing modules names have not been deprecated. Any deprecation or removal of the existing compression modules will occur no sooner than five years after the release of 3.14.

Desired solution

Deprecation warning if py-version is >= 3.14 ? In all cases ? Nothing until 5 year after the release of 3.14 ?

Additional context

https://docs.python.org/3.14/whatsnew/3.14.html#pep-784-adding-zstandard-to-the-standard-library

[jacobtylerwalls]

Let's do nothing until the deprecation actually happens. Sometimes there's disagreement about whether to go ahead with the planned deprecation.