How to reproduce:

1. Open attached project
2. Attach script Test.cs to any game object
- The script simply creates and removes listeners
- The code:
public UnityEvent Event;
private UnityAction m_onStartAction;

void Start () { m_onStartAction = OnTestFunc; }

void Update ()
{
Event.AddListener(m_onStartAction);
Event.RemoveListener(m_onStartAction);
}

private void OnTestFunc() {}

3. Play the scene
4. Open the Profiler window
- Note how much garbage is collected for BehaviourUpdate -> Test.Update()