gh-128916: Do not set `SO_REUSEPORT` on non-`AF_INET*` sockets (GH-128933)

* gh-128916: Do not set `SO_REUSEPORT` on non-`AF_INET*` sockets

Do not attempt to set ``SO_REUSEPORT`` on sockets of address familifies other
than ``AF_INET`` and ``AF_INET6``, as it is meaningless with these address
families, and the call with fail with Linux kernel 6.12.9 and newer.

* Apply suggestions from code review

Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>

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Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>