`IPv6Interface.ip` loses scope ID information

Bug report

Bug description:

Hi, I ran into an issue in my code (in multiplemonomials/multicast_expert) because putting an IPv6 address into an IPv6Interface, then accessing it via the ip property loses the scope ID information.

Here's a minimal example:

>> addr = ipaddress.IPv6Address("fe80::%10")
>> addr
IPv6Address('fe80::%10')
>> addr_with_prefix = ipaddress.IPv6Interface((addr, 64))
>> addr_with_prefix
IPv6Interface('fe80::%10/64')
>> addr_with_prefix.ip
IPv6Address('fe80::')

I would expect the last line to return IPv6Address('fe80::%10'), matching the value of addr. Not 100.0% sure this is a bug, but it's certainly something I would not expect since it's not in the documentation. So I'd appreciate if a note about this could be added to the docs if nothing else! Thank you!

Note that this issue is similar, but not the same thing: https://github.com/python/cpython/issues/88178

CPython versions tested on:

3.11

Operating systems tested on:

Windows

Linked PRs

• gh-129548

Start with the minimal IPv6Address and IPv6Interface example in the issue, then review linked PR gh-129548. Determine whether the agreed resolution is to preserve the scope ID in IPv6Interface.ip or document the current behavior; done means the chosen behavior or documentation matches that expectation.