use os-specific path-separators

This commit fixes a bug in the tests
where Unix path-separators were always
used to identify directory entries in
a zip-archive. That is wrong on
Windows, where Windows-path separators
have to be used.

datalad_next/archive_operations/tests/test_zipfile_archive_operations.py

@@ -2,6 +2,7 @@
 
 import zipfile
 from dataclasses import dataclass
+from os import pathsep
 from pathlib import Path
 from typing import Generator
 
@@ -77,7 +78,7 @@ def test_iterator(sample_zip: TestArchive):
     for item in items:
         item_name = (
             str(item.name) +
-            '/' if item.type == FileSystemItemType.directory
+            pathsep if item.type == FileSystemItemType.directory
             else str(item.name)
         )
         assert item_name in archive_ops