Wrong flag used for (set_)ipv6_multicast_hops

[NfNitLoop]

v1.1.4

rustix/src/backend/linux_raw/net/sockopt.rs

Lines 568 to 571 in 035acdc

	#[inline]
	pub(crate) fn set_ipv6_multicast_hops(fd: BorrowedFd<'_>, multicast_hops: u32) -> io::Result<()> {
	setsockopt(fd, c::IPPROTO_IP, c::IPV6_MULTICAST_HOPS, multicast_hops)
	}

rustix/src/backend/libc/net/sockopt.rs

Lines 617 to 620 in 035acdc

	#[inline]
	pub(crate) fn set_ipv6_multicast_hops(fd: BorrowedFd<'_>, multicast_hops: u32) -> io::Result<()> {
	setsockopt(fd, c::IPPROTO_IP, c::IPV6_MULTICAST_HOPS, multicast_hops)
	}

These two cases (and their getter counterparts) should use IPPROTO_IPV6, not IPPROTO_IP.

A library I use had to work around this bug:
https://github.com/al8n/hick/pull/49/changes#diff-5f92e53a99f51d3b30937d394280111bf28c84ff3f340c6ad82a08364d2e0cb0R24-R32

I'm just here making sure the issue got reported upstream. 🫡