Avoid using `any` type

I really like this package and the fact that a company with a strong engineering background is behind it.

But the use of `any` everywhere is really deterring me from using this.

Especially in the cases where types are most needed, such as rule creation:

https://github.com/cloudflare/authr/blob/3f6129d97d06e61033a7f237d84e35e678db490f/ts/src/rule.ts#L39

But the same pattern is used everywhere.

It is best practice to never use `any`, and in those cases where you truly don't know what the type should be, then use `unknown` type.