Replace nixUnstable with nixVersions.latest

Author: andreabedini

flake.nix

@@ -263,12 +263,12 @@
         );
 
         devShells = forEachSystemPkgs (pkgs:
-          let inherit (pkgs) mkShell nixUnstable cabal-install haskell-nix;
+          let inherit (pkgs) mkShell nixVersions cabal-install haskell-nix;
           in {
             default =
               mkShell {
                 buildInputs = [
-                  nixUnstable
+                  nixVersions.latest
                   cabal-install
                   haskell-nix.compiler.${compiler}
                 ];

overlays/haskell.nix

@@ -15,7 +15,7 @@ final: prev: {
         extraPkgconfigMappings = prev.haskell-nix.extraPkgconfigMappings or {};
         # Nix Flake based source pins.
         # To update all inputs, get unstable Nix and then `nix flake update --recreate-lock-file`
-        # Or `nix-shell -p nixUnstable --run "nix --experimental-features 'nix-command flakes' flake update --recreate-lock-file"`
+        # Or `nix-shell -p nixVersions.latest --run "nix --experimental-features 'nix-command flakes' flake update --recreate-lock-file"`
         sources = sources;
 
         # We provide a `callPackage` function to consumers for