Stricter typing for @fluent/langneg

Author: Pike

fluent-langneg/package-lock.json

@@ -49,8 +49,8 @@ interface NegotiateLanguagesOptions {
  *     This strategy requires defaultLocale option to be set.
  */
 export function negotiateLanguages(
-  requestedLocales: Array<string>,
-  availableLocales: Array<string>,
+  requestedLocales: Readonly<Array<string>>,
+  availableLocales: Readonly<Array<string>>,
   {
     strategy = "filtering",
     defaultLocale,