Pass phase in PauliList.from_symplectic example (#7436)

I believe this is what was intended when the example was originally added
(#5993), as this now matches the method signature, and the `phase`
on the previous line is no longer an unused variable.

qiskit/quantum_info/operators/symplectic/pauli_list.py

@@ -74,7 +74,7 @@ class PauliList(BasePauli, LinearMixin, GroupMixin):
         z = np.array([[True, True], [False, False]])
         x = np.array([[False, True], [True, False]])
         phase = np.array([0, 1])
-        pauli_list = PauliList.from_symplectic(z, x)
+        pauli_list = PauliList.from_symplectic(z, x, phase)
         print("4. ", pauli_list)
 
     **Data Access**