refactor(frontend): fix enum types in scripts/form

[ryoh827]

What

scripts/form.ts の enum の型を (string | {label: string; value: string;})[] に変更
fixed: #10881

Why

string[] の場合、下記の利用の仕方だと型が一致していないため

misskey/packages/frontend/src/components/MkFormDialog.vue

Lines 36 to 39 in b0344e0

	<MkSelect v-else-if="form[item].type === 'enum'" v-model="values[item]">
	<template #label><span v-text="form[item].label || item"></span><span v-if="form[item].required === false"> ({{ i18n.ts.optional }})</span></template>
	<option v-for="item in form[item].enum" :key="item.value" :value="item.value">{{ item.label }}</option>
	</MkSelect>

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment (frontend only)
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[syuilo]

🙏