The plugin is initialized with `lastTime` as null, meaning that if
`onGameTick` is called before `onInteractingChanged`, you can encounter
a case where after starting the client or plugin, `lastTime` has not yet
been set while `client.getLocalPlayer().getInteracting` is null (because
`onGameTick` gets sequenced before `onInteractingChanged` per tick),
causing an NPE when trying to compare a null Duration.
Fixesrunelite/runelite#5451
91369c41f0