message: ts: tweak to improve types
diff: @@ -289,7 +289,7 @@ export function each<I extends Dictionary<any> | any[] | readonly any[] | ArrayL
  this: Context,
  // Use unknown to avoid to infer to "any", which may disable typo check.
  value: I extends Dictionary<infer T> | (infer T)[] | readonly (infer T)[] | ArrayLike<infer T> ? T : unknown,
  - index?: I extends any[] | readonly any[] | ArrayLike<any> ? number : string,
  + index?: I extends any[] | readonly any[] | ArrayLike<any> ? number : keyof I,
  arr?: I
  ) => void,
  context?: Context
  