Fix Windows IPv6 bind option selection

[nkgotcode]

Fixes #2682.

This changes the Windows UDP socket setup so IPv4 packet-info options are only
enabled for IPv4 sockets and wildcard dual-stack IPv6 sockets. Non-wildcard
IPv6 binds such as [::1]:4433 no longer take the IPv4 option path.

Testing:

• cargo test -p quinn-udp --no-default-features

[Ralith]

Thanks for looking into this! The issue claims that the bug was introduced in b8e4d3b, which doesn't involve quinn-udp, so I don't think these changes are sufficient, and I'm not sure if they're necessary either, though they do make sense intuitively.

Please add an end-to-end test at the quinn level to be sure we capture (and don't regress) the behavior of the whole stack.