[3.14] GH-132983: Remove subclassing support from zstd types (GH-133694) (#133762)

GH-132983: Remove subclassing support from zstd types (GH-133694)

For consistency with ``bz2``, ``lzma``, and ``zlib``.
(cherry picked from commit bd7c5859c6c4f23877afdf6ab7b8209de50127a6)

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>