nng_socket_close may hang on windows

[Red-Li]

Describe the bug
nng_socket_close may hang on window in some situations, from the call stack, it is waiting for pipe close.

nng/src/core/socket.c

Line 691 in dba356d

while (!nni_list_empty(&sock->s_pipes)) {

Expected behavior
It should return normally

Actual Behavior
Hang

To Reproduce
Possible reproduce senario:
Create IPC/pair socket, but don't send any data for a period large than 5 seconds, and then close the socket.

** Environment Details **

• NNG Version: latest(v2.0)
• Windows 10
• Visual Studio 2022
• Static

Additional context
from my debugging, there is a issue in IOCP worker, timeout error does not handle correctly, which cause it exit unexpected.

nng/src/platform/windows/win_io.c

Line 42 in dba356d

if (olpd == NULL) {

Potential Fix has attached

winio.patch

[gdamore]

I think I fixed this a different way in commit 313e374

Can you try again?