Hackage search gives broken URLs

[Lysxia]

Reproduction steps:

1. Go to https://hackage.haskell.org/package/filepath-1.5.2.0
2. Press 's' to search for something, say takeDirectory.
3. Click on one of the results.
4. Get 404 because the URL is https://hackage.haskell.org/package/filepath-1.5.2.0/docs//package/template-haskell-2.19.0.0/docs/System-FilePath-Posix.html#v:takeDirectory

[hasufell]

@Kleidukos

[hasufell]

Might be due to GHC vendoring filepath in template-haskell: https://gitlab.haskell.org/ghc/ghc/-/tree/master/libraries/template-haskell/vendored-filepath/System?ref_type=heads

@bgamari