deprecate(n5): add deprecation warning to N5Store

zarr/n5.py

@@ -71,6 +71,16 @@ class N5Store(NestedDirectoryStore):
 
     """
 
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        warnings.warn(
+            "The N5Store is deprecated and will be removed in a Zarr-Python version 3, "
+            "see https://github.com/zarr-developers/zarr-python/issues/1274 and "
+            "https://github.com/zarr-developers/n5py for more information.",
+            FutureWarning,
+            stacklevel=2,
+        )
+
     def __getitem__(self, key: str) -> bytes:
         if key.endswith(zarr_group_meta_key):
             key_new = key.replace(zarr_group_meta_key, n5_attrs_key)