Downgrade to MacOS-13 since newest does not support < GHC-9.2

Author: lehins

.github/workflows/haskell.yml

@@ -38,7 +38,7 @@ jobs:
       fail-fast: false
       matrix:
         ghc: ["8.10.7", "9.2.8", "9.6.4", "9.8.2"]
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-13, windows-latest]
 
     env:
       # Modify this value to "invalidate" the cabal cache.