Use ghc-9.12.1 in GHA in stead of the prerelease

.github/workflows/haskell.yml

@@ -22,8 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # TODO: Change "9.12.0.20241031" --> "9.12.1" after official release
-        ghc: ["8.10.7", "9.2.8", "9.4.8", "9.6.4", "9.8.2", "9.10.1", "9.12.0.20241031"]
+        ghc: ["8.10.7", "9.2.8", "9.4.8", "9.6.4", "9.8.2", "9.10.1", "9.12.1"]
         cabal: ["3.10.2.1"]
         os: [ubuntu-latest, windows-latest, macOS-latest]
         cabal-flags: [""]
@@ -68,8 +67,6 @@ jobs:
         ghc-version: ${{ matrix.ghc }}
         cabal-version: ${{ matrix.cabal }}
         cabal-update: true
-        # TODO: remove once 9.12.1 is officially released
-        ghcup-release-channel: https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prereleases-0.0.8.yaml
 
     - name: Install liburing (on Linux)
       id: setup-liburing

cabal.project.release

@@ -1,7 +1,7 @@
 index-state:
   -- Bump this if you need newer packages from Hackage
-  -- current date: quickcheck-lockstep-0.6.0
-  , hackage.haskell.org 2024-12-03T16:12:22Z
+  -- current date: ghc-9.12.1
+  , hackage.haskell.org 2024-12-19T11:42:39Z
 
 packages: .
 
@@ -22,8 +22,9 @@ constraints: bloomfilter <0
 -- we could add a conditional on (+serialblockio) to remove this import automatically.
 import: cabal.project.blockio-uring
 
+-- TODO: remove this once all packages have upgraded their dependencies for ghc-9.12
 if impl(ghc >=9.12)
-  allow-newer: base
+  allow-newer: base, template-haskell, ghc-prim
 
 -- TODO: fix assembly error in text-2.1.2
 if (impl(ghc < 9.0) && os(windows))