Update CI

Add 9.12, drop 9.2, enable sempahore if available.

Author: michaelpj

.github/workflows/haskell.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ghc-version: ['9.10', '9.8', '9.6', '9.4', '9.2']
+        ghc-version: ['9.12', '9.10', '9.8', '9.6', '9.4']
         # Unlikely that we'll succeed on windows and fail on macos,
         # including it is just burning CI time. But windows could have
         # path or IO issues, so worth including

cabal.project

@@ -1,4 +1,4 @@
-index-state: 2024-12-23T14:00:00Z
+index-state: 2025-06-07T00:00:00Z
 
 packages:
          ./lsp
@@ -13,7 +13,5 @@ benchmarks: True
 package lsp
   flags: +demo
 
-package lsp-types
-  -- This makes a big difference here as lsp-types
-  -- has very many independent modules
-  ghc-options: -j4
+-- Useful if available
+semaphore: true