zlog: Replace usages of `env_logger` in tests with `zlog` (#31436)

Also fixes:
https://github.com/zed-industries/zed/pull/31400#issuecomment-2908165249

Release Notes:

- N/A *or* Added/Fixed/Improved ...
c0aa8f63fdBen Kunkle committed on 5/26/2025, 3:48:50 PM· committed by GitHubparent0c27aae
64 files changedLine totals unavailable