Pushing HLS' dependency to support Cabal 3.12, so we can use multi-repl feature in HLS codebase.

[soulomoon]

Historically, HLS using experience in HLS codebase itself is not great since the lack multiple home units support.
Since now Cabal 3.12 have released, and HLS also supports multi-repl feature, #4178.

We should be able to use this new feature in our own codebase. But our dependency is blocking us, some of them are:
cabal-doctest
entropy
extensions
fourmolu
ghc-paths
optparse-applicative
ormolu
pretty-simple

• extensions-0.1.0.1 not compatible with Cabal 3.12  kowainik/extensions#95 (comment)
• https://github.com/haskell/entropy Can we do a release for cabal 3.12? entropy#84 (comment)
• https://github.com/simonmar/ghc-paths Consider support for Cabal 3.12 so multiple home units repl can be used. simonmar/ghc-paths#31
• https://github.com/cdepillabout/pretty-simple

[soulomoon]

Current workaround forcing to use the new version of the following in cabal.project

allow-newer:
  *:Cabal,
  *:Cabal-syntax,
  *:optparse-applicative

source-repository-package
    type: git
    location: https://github.com/haskell/cabal.git
    subdir: Cabal Cabal-syntax
    tag : 3.12.0+0

================
update

Also need to clone the repo optparse-applicative by your side
and add the path it to cabal.project's packages