deps: upgrade to libuv 1.40.0
Notable changes:
- The UV_UDP_MMSG_FREE flag has been added.
- UV__EPROTO has been remapped from 4046 to -4046 for consistency with other error codes.
- On Windows, UTF-16 surrogate pairs are no longer replaced with the Unicode replacement character.
- uv_timer_get_due_in() has been added.
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
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