There's only been one version of Apple AirTags since their release in 2021, but Apple has announced some firmware updates since. The latest updates (we're now on version 2.0.36), announced in late 2022, were rolled out in a bid to stop the tags being used for stalking.
Now, AirTag owners can use Precision Finding to help locate an unknown AirTag that is moving with them. Also if an iPhone is 'awake', users will get a notification to alert them when an AirTag that's not with its owner is travelling with them. The AirTag will emit a sound to indicate it's been moved.