This fixes an issue identified with the WASAPI implementation in
https://github.com/ppy/osu-framework/pull/6088. It has no real effect
on current `master`, but fixes a deadlock that occurs with the
aforementioned framework branch when one lets a preview track play out
to the end - at this point all audio will stop and an attempt to perform
any synchronous BASS operation (playing another track, seeking) will
result in a deadlock.
It isn't terribly clear as to why this is happening precisely, but
there does not appear to be any need to stop and seek at that point,
so this feels like a decent workaround even if the actual issue is
upstream (and will unblock pushing out WASAPI support to users).