Replace environment variable parser with `zed --printenv` outputting JSON (#32637)

Closes: https://github.com/zed-industries/zed/issues/32445
Follow-up to: https://github.com/zed-industries/zed/pull/31799

Release Notes:

- Improved handling of environment variables

---------

Co-authored-by: Conrad Irwin <conrad@zed.dev>
71dbe88459Peter Tripp committed on 6/13/2025, 3:49:15 PM· committed by GitHubparentd280c95
8 files changedLine totals unavailable