Fix `Transition` events order

[RobinMalfait]

This PR fixes an issue where the order of {before,after}{Enter,Leave} don't happen at the correct time.

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Name	Status	Preview	Updated
headlessui-react	❌ Failed (Inspect)		Aug 18, 2022 at 2:20PM (UTC)
headlessui-vue	✅ Ready (Inspect)	Visit Preview	Aug 18, 2022 at 2:20PM (UTC)

[thecrypticace]

So, so, so much better! I still think the order of the before events should be reversed (out -> in) but I know why they're not in React at least. Can you give this a try with Vue to make sure we match the order in both places (or I can port this if you want). I have a feeling, for some reason, that the order might already be reversed there if you implement this.