Allow `Promise<void>` as return type of function passed to `enhance`

[Stadly]

The function passed to enhance is typed to return void:

kit/packages/kit/types/index.d.ts

Line 2072 in 3712121

}) => void

But it clearly accepts async functions.

Should it have been void | Promise<void>?

My linter says error Promise returned in function argument where a void return was expected @typescript-eslint/no-misused-promises.