Fix new ruff/flake8-type-checking TCH003 error (#2154)

TCH003 Move standard library import into a type-checking block

Author: DimitriPapadopoulos

tests/v3/test_buffer.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-import types
+from typing import TYPE_CHECKING
 
 import numpy as np
 import pytest
@@ -23,6 +23,9 @@
 )
 from zarr.testing.utils import gpu_test
 
+if TYPE_CHECKING:
+    import types
+
 try:
     import cupy as cp
 except ImportError: