spawn locks cwd on Windows

[Legend-Master]

Environment details

• OS: Windows 10
• OS version: 19045
• node-pty version: current main branch d6ce76a

Issue description

Calling spawn locks cwd directory so that you can't rename/delete that folder

Some times I would right click a folder and click "open in integrated terminal" in vscode and leave it, and then some time after when I try to rename/delete that folder, it will tell me that folder is locked (it doesn't tell you what's locking it, and since I don't know terminal/shell would do that, I did end up closing every app)

Windows Terminal fixed this by always spawning the shell process (or change it to later on) on C:\windows\system32: microsoft/terminal#5506 (comment)