fallbackLocale type mismatch for nested locale style

[bastibuck]

Describe the bug When using a fallbackLocale with the pages-router like described in the docs TypeScript doesn't like if you are using the nested style of locales. Flat keys works fine.

To Reproduce Steps to reproduce the behavior:

1. Follow setup instructions and use a nested locale file e.g.

   
   const en = {
   hello: {
   world: 'Hello, World!',
   user: 'Hello, {name}!',
   },
   } as const;

export default en;

2. Use the locale as `fallbackLocale` in `_app.tsx`
3. See error

**Expected behavior**
It should not throw an error regardless of using nested or flat style.

**Additional context**
It does work with the flat style of locale e.g.
```ts
const en = {
  'hello.world': 'Hello, World!',
  'hello.user': 'Hello, {name}!',
} as const;

export default en;

[QuiiBz]

Fix released in https://github.com/QuiiBz/next-international/releases/tag/1.2.4!