Fix cross-platform model_path assertion in FSDP config worker dict test

[dipeshbabu]

Summary

This fixes a cross-platform test failure in test_config_to_worker_dict.

The test previously asserted that d["model_path"] == "/tmp/model", which works on macOS/Linux but fails on Windows because Path("/tmp/model") is stringified using platform-specific path semantics. On Windows, str(Path("/tmp/model")) does not match the hardcoded POSIX path string.

What changed

Updated the assertion to compare against the actual serialized value derived from the config object:

• before: assert d["model_path"] == "/tmp/model"
• after: assert d["model_path"] == str(config.model_path)

Why this is correct

_config_to_worker_dict() is serializing a filesystem path from a Path object. The string representation of Path is platform-dependent, so the test should validate against str(config.model_path) rather than a Unix-only literal.

This keeps the implementation unchanged and makes the test valid on Windows, macOS, and Linux.

Scope

Test-only change. No runtime behavior changed.

Validation

Ran:

• uv run pytest ...
• uv run ruff check .

This resolves the Windows-specific failure while preserving the intended behavior of _config_to_worker_dict().