Use of `.version` attribute in `ipaddress` classes break many methods

Bug report

Bug description:

The following self-contained snippet behaves correctly with python 3.13 and with 3.14 IF I remove the version attribute.

But with 3.14 and the version attribute, the __eq__ method of AlwaysTrue is never called, and the script prints False for both.

import sys
from ipaddress import IPv4Network, IPv6Network


class AlwaysTrue:
    # without this attribute, everything works correctly
    version = 42

    def __eq__(self, other) -> bool:
        return True


print('sys.version', sys.version)
print('IPv4Network == AlwaysTrue', IPv4Network('43.48.0.0/12') == AlwaysTrue())
print('IPv6Network == AlwaysTrue', IPv6Network('::eeff:ae3f:d473/128') == AlwaysTrue())

CPython versions tested on:

3.14

Operating systems tested on:

macOS and linux

Linked PRs

• gh-141651
• gh-141842