Recognize onnxruntime-windowsml in onnxruntime version detection

When users install the Windows ML onnxruntime variant
(`pip install onnxruntime-windowsml`), `find_spec("onnxruntime")` still
resolves successfully, but none of the package names in the
metadata-lookup fallback match, so `importlib_metadata.version(pkg)`
fails for every candidate and `_onnx_available` ends up False (see #13062).

Add `onnxruntime-windowsml` to the candidate list alongside the other
vendor-specific wheels (DirectML, CANN, OpenVINO, …) so installations
that ship only this variant are detected.

Fixes #13062

Author: Ricardo-M-L

src/diffusers/utils/import_utils.py

@@ -140,6 +140,7 @@ def _is_package_available(pkg_name: str, get_dist_name: bool = False) -> tuple[b
         "onnxruntime-rocm",
         "onnxruntime-training",
         "onnxruntime-vitisai",
+        "onnxruntime-windowsml",
     )
     _onnxruntime_version = None
     # For the metadata, we have to look for both onnxruntime and onnxruntime-x