fix(types): type translation variable keys

[ShGKme]

Before

// ✅ Ok
t('app', 'Hello, {name}!', { name: 'Alice' })

// ✅ Ok
t('app', 'Hello, {name}!', { user: 'Alice' })

// ✅ Ok
t('app', 'Hello, {name}!', {})

After

// ✅ Ok
t('app', 'Hello, {name}!', { name: 'Alice' })

// ❌ Object literal may only specify known properties, and 'user' does not exist in type 'TranslationVariables<"Hello, {name}!">'
t('app', 'Hello, {name}!', { user: 'Alice' })

// ❌ Argument of type '{}' is not assignable to parameter of type 'TranslationVariables<"Hello, {name}!">'.
//  Property 'name' is missing in type '{}' but required in type 'TranslationVariables<"Hello, {name}!">'
t('app', 'Hello, {name}!', {})