dont propose to restart ghc when not available

## Is your enhancement request related to a problem?

I have almost nothing in my global PATH and configure tooling on a per-project basis.
Only when entering a development shell (via `nix develop`), I get my LSP, compilers etc. available.

My current issue is that whenever I open my haskell projects with neovim for a quick look/edit without entering the nix-shell, I get this annoying popup "Failed to find the GHC version of this Cabal project.". This takes the focus and thus I first have to escape the prompt before doing anything. Restarting is bound to fail as there is no ghc in PATH


## Describe the solution you'd like

I would like to be able to disable the prompt but still get the error. If there is a LSP knob for that, it should be in hls but maybe it's something to configure in neovim, I am not sure yet.

## Describe alternatives you've considered

None

## Additional context

First (wrongly) reported at
https://github.com/mrcjkb/haskell-tools.nvim/issues/338#issuecomment-1903928432

https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initializeError

The payload names no implementation files or tests. Start by tracing the HLS handling for a missing GHC version and its restart prompt, then check the LSP initialize-error reference; done means a configuration can suppress the prompt while retaining the error.

Written by the indexing model from the issue text.