router.asPath includes hash fragment on client side

### What version of Next.js are you using? 10.0.9 ### What version of Node.js are you using? 14.15.4 ### What browser are you using? n/a ### What operating system are you using? n/a ### How are you deploying your application? n/a ### Describe the Bug I have found that `router.asPath` contains the current hash fragment, if there is one, such as `/my-page/#my-subheading`. This was unexpected to me. [The docs](https://nextjs.org/docs/api-reference/next/router#router-object) mention that it includes the query string if there is one, but it doesn't say anything about the hash fragment. Hash fragments never make it to the server side, and I'd expect the same behaviour from the router both client and server side, so it being included in this field feels to me like a bug. ### Expected Behavior `router.asPath` does not include a hash fragment. ### To Reproduce 1. Make a component which uses `const router = useRouter()`. 2. Have it output in some way `router.asPath`. 3. Navigate to this page with a fragment as part of the URL.