feat: use const type parameters for useTranslation()

TypeScript 5.0 has introduced const type parameters [1]. These indicate
that a more specific type is preferred over a more general one. As
a result, the resulting UseTranslationResponse will be more precise
and retain the passed-in namespace and prefix. This can be used by
extractors and other tooling to find out exactly which key is
accessed by a translation function call.

[1]: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-5-0.html#const-type-parameters

Author: emersion

index.d.ts

@@ -97,8 +97,8 @@ export type FallbackNs<Ns> = Ns extends undefined
     : _DefaultNamespace;
 
 export function useTranslation<
-  Ns extends FlatNamespace | $Tuple<FlatNamespace> | undefined = undefined,
-  KPrefix extends KeyPrefix<FallbackNs<Ns>> = undefined,
+  const Ns extends FlatNamespace | $Tuple<FlatNamespace> | undefined = undefined,
+  const KPrefix extends KeyPrefix<FallbackNs<Ns>> = undefined,
 >(
   ns?: Ns,
   options?: UseTranslationOptions<KPrefix>,