Absolutize LSP and DAP paths more conservatively (#42482)

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

crates/project/src/debugger/dap_store.rs

@@ -262,8 +262,8 @@ impl DapStore {
                 let user_installed_path = dap_settings.and_then(|s| match &s.binary {
                     DapBinary::Default => None,
                     DapBinary::Custom(binary) => {
-                        // if `binary` is absolute, `.join()` will keep it unmodified
-                        Some(worktree.read(cx).abs_path().join(PathBuf::from(binary)))
+                        let path = PathBuf::from(binary);
+                        Some(worktree.read(cx).resolve_executable_path(path))
                     }
                 });
                 let user_args = dap_settings.map(|s| s.args.clone());