tests/test_cli: fix leaking file descriptor

Ensure opened file is closed before the test ends.

Author: dlech

tests/test_cli.py

@@ -217,7 +217,7 @@ async def test_download_connection_error(self):
             # Create args
             args = argparse.Namespace(
                 conntype="ble",
-                file=open(temp_path, "r"),
+                file=stack.enter_context(open(temp_path, "r")),
                 name="MyHub",
                 start=False,
                 wait=False,