resolve #5882

Consider the following structure:

<!-- basic.vue -->
<script lang="ts" setup>
  defineProps<{
    foo: string;
    bar: string;
  }>();
</script>

<!-- comp.vue -->
<script lang="ts" setup>
  import Basic from "./basic.vue";
</script>

<template>
  <Basic />
</template>

When the fallthroughAttributes option is enabled on Comp, Comp inherits all props from Basic, allowing us to get prop completions for Basic when using Comp.

By default, however, the props inherited from Basic are all optional. This means we cannot enforce passing those required props when using Comp. At the same time, even if the required props from Basic are passed to Comp, Basic will still report missing prop errors.

After enabling the new checkRequiredFallthroughAttributes option on Comp, Comp will inherit Basic's props exactly as they are, and the missing prop errors on Basic inside Comp will disappear. This is because doing so is equivalent to promising that these required props should be passed when using Comp. Additionally, if some of the props required by Basic have already been passed directly to Basic, those props will be excluded from the inherited props.