gh-91896: Revert some very noisy DeprecationWarnings for ByteString

[AlexWaygood]

Emitting a DeprecationWarning every time ByteString is accessed or imported from collections.abc or typing is too noisy, as it effectively forbids anybody from doing from collections.abc import * or from typing import * if they want to avoid DeprecationWarnings. from typing import *, in particular, appears to be a common idiom so this looks as though it would be too disruptive. This was an error on my part; I'm sorry for the code churn here.

This PR reverts most of #104294, most of #104422, and all of #104416.

• Issue: Deprecate and schedule removal of collections.abc.ByteString and typing.ByteString #91896

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📚 Documentation preview 📚: https://cpython-previews--104424.org.readthedocs.build/

[JelleZijlstra]

Thanks!

I tried to think of ideas to do this better and couldn't think of anything:

• Remove ByteString from __all__ for 3.12: this would be a backward compatibility break
• Change the import * code to suppress DeprecationWarnings: way too magical
• In the module __getattr__, somehow detect that we're being called from import *: no idea how to do that elegantly

[AlexWaygood]

Yeah, it's pretty frustrating that there isn't a better way of doing this :(

And this only happens because collections.abc and typing are following "best practices" and defining __all__. from ast import * doesn't cause any deprecation warnings to be emitted, even after 376137f, because ast doesn't define __all__, so the * import just looks at what's in globals(), and the module-level __getattr__ method is never triggered.

It feels somewhat perverse that defining __all__ makes life more difficult here :(