fix: address review comment — remove standalone regression test per maintainer feedback

Signed-off-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>

Author: NIK-TIGER-BILL

tests/test_store/test_stateful.py

@@ -51,23 +51,3 @@ def mk_test_instance_sync() -> ZarrStoreStateMachine:
     run_state_machine_as_test(mk_test_instance_sync)  # type: ignore[no-untyped-call]
 
 
-def test_delete_dir_prefix_matching() -> None:
-    """Regression test for delete_dir prefix matching bug (GH#3977).
-
-    Verifies that delete_dir bookkeeping only removes exact path matches
-    and true descendants, not unrelated nodes that merely share a string
-    prefix (e.g. ``6/faNT…`` must NOT be deleted when removing ``6/f``).
-    """
-    all_groups = {"6/f", "6/faNT7p7jvJsO3_C._HYi", "other"}
-    all_arrays = {"6/f/child", "6/other"}
-    path = "6/f"
-
-    matches = set()
-    for node in all_groups | all_arrays:
-        if node == path or node.startswith(path + "/"):
-            matches.add(node)
-
-    assert matches == {"6/f", "6/f/child"}
-    assert "6/faNT7p7jvJsO3_C._HYi" not in matches
-    assert "other" not in matches
-    assert "6/other" not in matches