deps: upgrade to libuv 1.38.1

Notable changes:

- A probable compiler bug in VS2019 was causing a
  failed assertion in libuv which appeared to the
  user as though the system clock was drifting. The
  `uv_hrtime()` code on Windows has been rearranged
  to work around the issue.
- On Linux, `uv_loadavg()` attempts to read from
  `/proc/loadavg` before falling back to calling
  `sysinfo()`. This works around a bug in LXC.
- A deadlock in the Windows TTY code has been fixed.
- An issue on macOS related to monotonic clocks jumping
  back in time has been worked around.

PR-URL: https://github.com/nodejs/node/pull/34187


Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>