Bumping haskell-language-server versions don't occur automatically

[baco]

There are periodic releases of the haskell-language-server, for instance, as of the time of writing this issue, v2.8.0 has already been released.

Contrary to other Mason packages, those releases are not detected unless there is a PR for the manual version bump.

Fix this registry's entry for that package so it's able automatically detect and upgrade package's version without relying on a manual PR.