fix: type in ts5

[AkaraChen]

Describe your changes

There are types at '/node_modules/astro-i18next/dist/types/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'astro-i18next' library may need to update its package.json or typings.ts(7016)

Fixes #(issue)

Checklist

• I have performed a self-review of my code
• I have added thorough tests
• I have updated the docs