Deflake the socket_inet_loopback test
Deflake the socket_inet_loopback test

Don't close sockets for writing otherwise sendto can fail with EPIPE.

PiperOrigin-RevId: 419751558

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor