`quopri` uses conditional `binascii` import, when it is always available

Feature or enhancement

This module is quite old, it uses a conditional import of binascii since times when it was possible to not have it when zlib was missing: https://github.com/python/cpython/blob/13cb8ca3da75d6fe2a1114e58c24ca681fee411f/Lib/quopri.py#L12-L17

However, right now it is always available under all python implementations (like RustPython and PyPy).

• RustPython: https://github.com/RustPython/RustPython/blob/main/stdlib/src/binascii.rs

• PyPy: https://github.com/pypy/pypy/blob/9abbb4f358a5c308aefb85652a229cc98f899e13/pypy/module/binascii/moduledef.py#L22-L23

So, we can simplify the implementation and remove a lot of duplicated code, example: https://github.com/python/cpython/blob/13cb8ca3da75d6fe2a1114e58c24ca681fee411f/Lib/quopri.py#L51-L99

There are also several helper functions with public names, which are not in __all__ which will be unused after this. We can keep them and deprecate their use.

Since binascii is always available, python implementation is never used anyway.

So, the main pro:

• We can remove some dead code

There are several cons to my proposal:

• There are no real user reported problems
• The module is old and stable
• It does not require a lot of maintaince

I will open a draft PR, so people can see the amount of changes and decide better with that.

Should we do this?

Linked PRs

• gh-133897