Deprecate and schedule removal of collections.abc.ByteString and typing.ByteString

The current docstring of collections.abc.ByteString is:

    """This unifies bytes and bytearray.

    XXX Should add all their methods.
    """

Let's do that last thing. This will be useful for typing code that accepts both bytes and bytearray, especially with my proposal in PEP-688 to make bytes no longer acceptable as a shortcut for bytearray in the type system.

cc @rhettinger for collections.abc

Linked PRs

• gh-91896: Deprecate collections.abc.ByteString #102096
• gh-91896: Improve visibility of ByteString deprecation warnings #104294
• gh-91896: Fixup some docs issues following ByteString deprecation #104422
• gh-91896: Revert some very noisy DeprecationWarnings for ByteString #104424