Update ghc versions in GitHub workflow matrix

Author: neilmayhew

.github/workflows/haskell.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ghc: ['8.8.4', '8.10.7', '9.0.2', '9.2.8', '9.4.8', '9.6.4', '9.8.2']
+        ghc: ['8.8.4', '8.10.7', '9.0.2', '9.2.8', '9.4.7', '9.6.6', '9.8.4', "9.10.1", "9.12.1"]
       fail-fast: false
 
     name: Build with GHC ${{ matrix.ghc }}