The Lightning VJP logic needs to be updated to use the new operator arithmetic

[josh146]

While reviewing PennyLaneAI/pennylane#4358, I noticed that Lightning is still creating Hamiltonians when VJPs are requested:

pennylane-lightning/pennylane_lightning/lightning_qubit.py

Line 687 in 8608a6e

ham = qml.Hamiltonian(dy, [m.obs for m in measurements])

This logic will soon be accessible to PennyLane, and the Hamiltonian class is marked for deprecation - just wanted to make a note of this in case it was missed in previous upgrade work.