Update for removing qutip.qip in dev.major (#146)

VQA module wrongly used the qutip.qip module, which is removed in qutip-v5.

Update the Measurement class and expand the measurement operator because calling the qutip measurement functions.

See also qutip/qutip#1890.

Author: BoxiLi

src/qutip_qip/circuit.py

@@ -141,9 +141,11 @@ def measurement_comp_basis(self, state):
         else:
             raise ValueError("target is not valid")
 
-        return measurement_statistics(
-            state, measurement_ops, targets=self.targets
-        )
+        measurement_ops = [
+            expand_operator(op, N=n, targets=self.targets)
+            for op in measurement_ops
+        ]
+        return measurement_statistics(state, measurement_ops)
 
     def __str__(self):
         str_name = ("Measurement(%s, target=%s, classical_store=%s)") % (