Auto merge of #86662 - mockersf:fix-86620-link-unknown-location, r=jyn514

fix dead link for method in trait of blanket impl from third party crate

fix #86620

* changes `href` method to raise the actual error it had instead of an `Option`
* set the href link correctly in case of an error

I did not manage to make a small reproducer, I think it happens in a situation where
* crate A expose a trait with a blanket impl
* crate B use the trait from crate A
* crate C use types from crate B
* building docs for crate C without dependencies

r? `@jyn514`