Merge pull request #6755 from equal1/fix-experiment-connection

Fix `Experiment.last_data_set` to pass `self.conn` to `load_by_id`

src/qcodes/dataset/experiment_container.py

@@ -183,7 +183,7 @@ def last_data_set(self) -> DataSetProtocol:
         run_id = get_last_run(self.conn, self.exp_id)
         if run_id is None:
             raise ValueError("There are no runs in this experiment")
-        return load_by_id(run_id)
+        return load_by_id(run_id, conn=self.conn)
 
     def finish(self) -> None:
         """