netbsd-tests: Fix the libc stat_socket test

The test tries to connect a socket to a closed port at 127.0.0.1. It
sets O_NONBLOCK on the socket first and expects to get EINPROGRESS from
connect(2), but this is not guaranteed, ECONNREFUSED is possible.
Handle both cases, and re-enable the test.

PR: 240621
MFC after: 1 week
Sponsored by: The FreeBSD Foundation