Remove winpty support #842
Description
I think we should go ahead and do this at this point, conpty has been in Windows for a long time and should remove winpty support completely from node-pty and VS Code. This will reduce complexity, fix a bunch of compliance related things and rip out this unmaintained code from a legacy component we haven't touched in years and don't recommend ever using.
Conpty originally landed in "Autumn/Fall 2018 release of Windows 10" which I believe is 1809 (build 17763.8148) according to the announcement post. Mainstream OS support has ended for that.
According to telemetry out of all the terminals created in the past week, it looks like < 0.1% are created on versions of Windows that do not have conpty.