Cooldown updates do not clear old cooldown timer

[dori4n]

When a button cooldown is updated via the interactive service, the previous timer that shows that a button is on cooldown is not cleared, and all timers will continue to update the text until they run out, this causes the time shown to flicker between two or more values.
The timer should be cleared when the new one is added such that there is only one timer active per button.
Probably something going wrong in setCountdown() src/alchemy/preact/Cooldown.tsx. Please fix. 😗