These stop calls were put in place during a time when the "pump"
threads were not easily interrupted. Usually this was due to
being forced to work with opaque IO streams rather than the actual
channels. At this point, with Thread#stop going away and still
causing log noise, we have decided to remove all calls.

This code was used primarily by the few remaining non-popen-based
command launches (usually which read the streams to completion and
do not need to be interrupted), and for much of IO on Windows
(since we have not finished porting native IO logic to Windows).
If the removal of these calls leads to leaky pump threads, we will
find an alternative way or prioritize the completion of native IO
on Windows.