- construct the correct path to the test library based on the location
of package.json
- run scripts from the package root where they were defined
- run tests in the directory of the defining file

Release Notes:

- Debugger Beta: fixed running JS tests when the worktree root is above
the location of package.json.

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Co-authored-by: Anthony <anthony@zed.dev>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>