Update examples/active-class-name (#62506)
### Description
The current implementation of the activeClassName example doesn't
support the `UrlObject` type for the "href" Link prop.
For example
```
<ActiveLink
activeClassName="active"
className="nav-link"
href={{
pathname: "/[slug]",
query: {
slug: "dynamic-route",
},
}}
>
Dynamic Route
</ActiveLink>
```
won't work.
### Suggestion
We can use the `resolveHref` function to handle all cases.
Co-authored-by: Sam Ko <sam@vercel.com>
