It's not clear to me if dropping support for this functionality was intentional.

Chain of events:

- #21689 removed test coverage due to a misunderstanding due, I believe, to this functionality being generally supported by all platforms except macOS which does not and returns a different format
- #21756 removed support and caused this regression
- #21690 restores the test coverage that would have caught this regression

Currently, neither the test coverage before #21689 nor the coverage restored by #21690 pass since the merge of #21756.

{
    if (!IsIPv4())
        return false;
    assert(sizeof(*pipv4Addr) == m_addr.size());
    memcpy(pipv4Addr, m_addr.data(), m_addr.size());
    return true;
}
/**
 * Try to get our IPv6 address.
 *
 * @param[out] pipv6Addr The in6_addr struct to which to copy.
 *
 * @returns Whether or not the operation was successful, in particular, whether
 *          or not our address was an IPv6 address.
 *
 * @see CNetAddr::IsIPv6()
 */
bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const