fix chunk grid metadata exclusion (TGSAI#662)

Author: tasansal

src/mdio/builder/xarray_builder.py

@@ -211,7 +211,7 @@ def to_xarray_dataset(mdio_ds: Dataset) -> xr_Dataset:  # noqa: PLR0912
 
         # Add array attributes
         if v.metadata is not None:
-            metadata_dict = v.metadata.model_dump(exclude_none=True, exclude={"chunkGrid"})
+            metadata_dict = v.metadata.model_dump(exclude_none=True, exclude={"chunk_grid"})
             data_array.attrs.update(metadata_dict)
         if v.long_name:
             data_array.attrs["long_name"] = v.long_name