Allow as for no-dynamic-keys rule

[shaedrich]

What rule do you want to change?
@intlify/vue-i18n/no-dynamic-keys

Does this change cause the rule to produce more or fewer warnings?
fewer

How will the change be implemented? (New option, new default behavior, etc.)?
new option (skipTSAsExpression)

Please provide some example code that this change will affect:

<template>
<span>{{ t(`binary-question.${isPositive.toString()}.title` as `binary-question.${'true' | 'false'}.title` }}</span>
</template>

<script lang="ts" setup>
let isPositive: bool = true;
</script>

What does the rule currently do for this code?
Disallow any dynamic translation key

What will the rule do after it's changed?
Only disallow dynamic translation keys when their type isn't narrowed down via template string literal type.

Additional context