2 qubit env transitions

[Farquhar13]

@VishChaudhary this commit (8d9e546) works as a temporary work around, but it would be better if we match the self.transition_history across the 1-qubit and 2-qubits environments instead. Doing it this way would be more consistent and wouldn't require any code additions to save_results.py

These should match and that should fix the issue:

• 1 qubit: https://github.com/Farquhar13/relaqs/blob/main/src/relaqs/environments/single_qubit_env.py#L127
• 2 qubit: https://github.com/Farquhar13/relaqs/blob/main/src/relaqs/environments/noisy_two_qubit_env.py#L532