Fix test

Author: dcherian

src/zarr/core/buffer/core.py

@@ -457,7 +457,12 @@ def __repr__(self) -> str:
         return f"<NDBuffer shape={self.shape} dtype={self.dtype} {self._data!r}>"
 
     def all_equal(self, other: Any) -> bool:
-        return np.array_equal(self._data, other, equal_nan=True)
+        # other is expected to be a scalar
+        # use array_equal to obtain equal_nan=True functionality
+        result = np.array_equal(
+            self._data, np.broadcast_to(other, self._data.shape), equal_nan=True
+        )
+        return result
 
     def fill(self, value: Any) -> None:
         self._data.fill(value)