findExecutable in Wrapper.hs execute prebuilt's hls rather than 'cabal build''s output

[ZichaoNickFox]

Is your enhancement request related to a problem? Please describe.

1. According https://haskell-language-server.readthedocs.io/en/stable/contributing/contributing.html#building-with-nix. Using nix-shell to execute wrapper.
2. Executing cabal run haskell-language-server-wrapper lsp
3. Code run to

   haskell-language-server/exe/Wrapper.hs

   Line 157 in be30f3e

   mexes <- liftIO $ traverse findExecutable candidates

4. The mexe found by findExecutable turns out as following. Rather than exe from dist-newstyle which contains cabal build's output.

mexes =
  [ Just "/nix/store/x4njcm292dm8wgqjhxyp4jxcx77sz3x2-haskell-language-server-2.10.0.0/bin/haskell-language-server-9.8.4"
  , Just "/nix/store/x4njcm292dm8wgqjhxyp4jxcx77sz3x2-haskell-language-server-2.10.0.0/bin/haskell-language-server"
  ]

5. The exes on nix store is added in here. Rather than cabal build's output
   

   haskell-language-server/flake.nix

   Line 71 in be30f3e

   hpkgs.haskell-language-server

Describe the solution you'd like

1. Maybe upgrade the documentation https://haskell-language-server.readthedocs.io/en/stable/contributing/contributing.html#building-with-nix. Using nix to compile and startup Wrapper?
2. Maybe change findExecutable way to find the cabal build's exe?
3. Maybe precompile tools chains than import?

   haskell-language-server/flake.nix

   Line 71 in be30f3e

   hpkgs.haskell-language-server

Describe alternatives you've considered

Or I need help, Maybe my execution method has issue.

Additional context

None.