musl: backport patches to fix pthread_cond_wait with PI mutex
https://github.com/pulseaudio/pulseaudio/blob/master/src/pulsecore/mutex-posix.c#L55
https://github.com/pulseaudio/pulseaudio/blob/master/src/pulse/thread-mainloop.c#L118
413a8f8917
pulseaudio uses a prio-inheriting mutex since the above revision
that is paised with a condition variable; the behavior of this
was broken in musl until the above patches, which would result
in pulseaudio deadlocking with gstreamer pulsesink (most often
with webkit) and possibly other things.
Fixes https://github.com/void-linux/void-packages/issues/15631
53d00fffc2