fix: correct test_zmq_write_read_roundtrip to match read() return signature

read() returns a single value, not a tuple. The test incorrectly
unpacked into (result, ok) causing ValueError on CI.

Author: GaneshPatil7517

tests/test_concore.py

@@ -408,7 +408,7 @@ def recv_json_with_retry(self):
         concore.write("roundtrip_test", "data", original_data)
 
         # Read should return original data (simtime stripped)
-        result, ok = concore.read("roundtrip_test", "data", "[]")
+        result = concore.read("roundtrip_test", "data", "[]")
         assert result == original_data