Use get_duck_array instead of get_array

Fix `TypeError: Implicit conversion to a NumPy array is not allowed. Please use `.get()` to construct a NumPy array explicitly.` on https://github.com/pydata/xarray/blob/1bb867d573390509dbc0379f0fd318a6985dab45/xarray/core/indexing.py#L514

Author: weiji14

cupy_xarray/kvikio.py

@@ -58,7 +58,7 @@ class EagerCupyZarrArrayWrapper(ZarrArrayWrapper):
     def __array__(self):
         return self._array[:].get()
 
-    def get_array(self):
+    def get_duck_array(self):
         # total hack: make a numpy array look like a Zarr array
         # this gets us through Xarray's backend layers
         return DummyZarrArrayWrapper(self._array[:].get())