remote: Wrap `uname` invocation in `sh` for `nu` shell (#40084)

Closes https://github.com/zed-industries/zed/pull/39994

Release Notes:

- Fixed remoting not working when nushell is set as the default shell on
the remote target
025938b4a5Lukas Wirth committed on 10/14/2025, 6:51:08 AM· committed by GitHubparentcc9af8d
2 files changedLine totals unavailable