This fixes the problem of the Zig extension picking up `zls` from the
shell env but `zls` then failing to launch because it cannot find `zig`.
Scenario in which this happens:
- `.envrc` in a project that sets `$PATH` up
- in that `$PATH` there's `zls` and `zig`
- Zed is started from Dock
- Project is opened
- Shell env from project directory is loaded and used to get to `zls`
- `zls` is then started, without that environment set on the process
- `zls` cannot find `zig`
Release Notes:
- N/A
Co-authored-by: Marshall <marshall@zed.dev>
da0d968a2c