fix(core): not to cache entire workspace root (#28552)

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## Current Behavior
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- if directory is workspace root, when walking through the directory, it
will include the directory root path, then will strip prefix, it will be
empty string. it will return "*" as a found path.
- When copying "*", it will run into a recursive loop because it will
try to copy the walkspace root with node_modules into
node_modules/.cache/nx

## Expected Behavior
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## Related Issue(s)
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merged. -->

Fixes #28393

packages/nx/src/native/walker.rs

@@ -52,7 +52,12 @@ where
         .filter_map(move |entry| {
             entry
                 .ok()
-                .and_then(|e| e.path().strip_prefix(&base_dir).ok().map(|p| p.to_owned()))
+                .and_then(|e|
+                    e.path()
+                    .strip_prefix(&base_dir).ok()
+                    .filter(|p| !p.to_string_lossy().is_empty())
+                    .map(|p| p.to_owned())
+                )
         })
 }