ZarrParser fails when zarr store is nested inside object store root #912

import numpy as np
import xarray as xr
from obstore.store import LocalStore
from obspec_utils.registry import ObjectStoreRegistry                                                                                                          
from virtualizarr.parsers.zarr import ZarrParser                                                                                                               
                                                                                                                                                                
# Zarr store nested inside the object store root                                                                                                               
parent_dir = "/tmp/bucket_root"
storepath = f"{parent_dir}/subdir/data.zarr"                                                                                                                    
                                                                                                                                                                
ds = xr.Dataset({"temp": (("x", "y"), np.arange(12, dtype="float32").reshape(3, 4))})                                                                          
ds.to_zarr(storepath, consolidated=False, zarr_format=2)                                                                                                        
                                                                                                                                                                
store = LocalStore(prefix=parent_dir)                                                                                                                          
registry = ObjectStoreRegistry({f"file://{parent_dir}": store})
                                                                                                                                                                
parser = ZarrParser()
parser(url=storepath, registry=registry)  # raises GroupNotFoundError