toast.promise renders 3 toasts on resolve

[Nils Wiesinger]

Hey, really enjoying the package so far!
When switching over our existing toasts to this package I noticed that after a toast.promise resolves the promise there's 3 toasts instead of one success toast like this:

Reproduction: https://stackblitz.com/edit/github-zwebrm?file=plugins%2Fsonner.client.ts,package.json,app.vue,nuxt.config.ts

[Robert Shaw]

Thank you for bringing this issue to my attention. I have reviewed the reproduction results and I will handle it as soon as possible.

[Robert Shaw]

fixed #35

[Behon Baker]

Thanks for the fix