util: Fix invalid powershell redirection syntax used in uni shell env capture (#43390)

Closes  https://github.com/zed-industries/zed/issues/42869

Release Notes:

- Fixed shell env sourcing not working with powershell on unix systems
f7772af197Lukas Wirth committed on 11/24/2025, 11:11:45 AM· committed by GitHubparent2f46e6a
1 file changedLine totals unavailable