Fixes a regression caused by #42135 where LSP and DAP binaries weren't
being used from `PATH` env var
Now we absolutize the path if (path is relative AND (path has multiple
components OR path exists in worktree)).
- Relative paths with multiple components might not exist in the
worktree because they are ignored. Paths with a single component will at
least have an entry saying that they exist and are ignored.
- Relative paths with multiple components will never use the `PATH` env
var, so they can be safely absolutized
Release Notes:
- N/A
2bcfc12951