add enter and exit methods to groups.

Author: dikwickley

src/zarr/core/group.py

@@ -7,7 +7,7 @@
 import warnings
 from collections import defaultdict
 from dataclasses import asdict, dataclass, field, fields, replace
-from typing import TYPE_CHECKING, Literal, TypeVar, assert_never, cast, overload
+from typing import TYPE_CHECKING, Literal, TypeVar, assert_never, cast, overload, Self
 
 import numpy as np
 import numpy.typing as npt
@@ -1752,6 +1752,12 @@ def open(
         obj = sync(AsyncGroup.open(store, zarr_format=zarr_format))
         return cls(obj)
 
+    def __enter__(self) -> Self:
+        return self
+
+    def __exit__(self) -> None:  # noqa: PYI036
+        self.store.close()
+
     def __getitem__(self, path: str) -> Array | Group:
         """Obtain a group member.