Fix shell escaping in getting current env (#53335)

Credit to Dario Weißer for bringing this to our attention.

Self-Review Checklist:

- [ ] I've reviewed my own diff for quality, security, and reliability
- [ ] Unsafe blocks (if any) have justifying comments
- [ ] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [ ] Tests cover the new/changed behavior
- [ ] Performance impact has been considered and is acceptable

Closes #ISSUE

Release Notes:

- Fixed a bug where a cleverly crafted directory name could lead to
remote code execution
ac6117a9d8Conrad Irwin committed on 4/8/2026, 2:56:06 AM· committed by GitHubparent30e7e8b
2 files changedLine totals unavailable