[TypeScript] cacheKey arguments array isn't automatically typed

[dylang]

In v5, the cacheKey arguments were automatically typed based on the method signature. In v6, the cacheKey arguments extend unknown instead of getting them from the original function.

Example error:

const example = mem(
  (str: string, strArray: string[]) => { /* do stuff */  },
  {
    // Typescript error on strArray: 
    // TS2461: Type 'unknown' is not an array type.
    cacheKey: ([str, strArray]) => [str, ...strArray].join()
    //                                   ^^^^^^^^^^^ <- Example error
  }
);

Workaround:

const example = mem(
  (str: string, strArray: string[]) => { /* do stuff */  },
  {
    // Repeat the types of the arguments inside of [ ].
    cacheKey: ([str, strArray]: [string, string[]]) => [str, ...strArray].join()
    //                        ^^^^^^^^^^^^^^^^^^^^ <- Example workaround
  }
);

I'm not sure if this can be fixed using generics, so it might just be some documentation for those confused when upgrading.