Switch to nix based github action for macos

.github/workflows/ci.yaml

@@ -48,18 +48,16 @@ jobs:
       - run: mix compile --warnings-as-errors
       - run: mix test --exclude skip:true --trace
 
-  macos-test:
+  macos:
     runs-on: macos-11
     name: Test - Elixir (MacOS)
     steps:
-      - uses: actions/checkout@v3
-      - name: Install erlang and elixir
-        run: |
-          brew install erlang elixir
-          mix local.hex --force
-          mix local.rebar --force
-      - run: mix deps.get
-      - run: mix test --trace
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - uses: DeterminateSystems/flake-checker-action@main
+      - run: nix develop --command mix deps.get
+      - run: nix develop --command mix test --trace
 
   lint:
     runs-on: ubuntu-22.04

flake.nix

@@ -0,0 +1,24 @@
+{
+  description = "Elixir Development Environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+  };
+
+  outputs = { self, nixpkgs, ... }:
+    let
+      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
+        pkgs = import nixpkgs { inherit system; };
+      });
+    in
+      {
+        devShells = forAllSystems ({ pkgs }: {
+          default = pkgs.mkShell {
+            packages = with pkgs; [
+              elixir
+            ];
+          };
+        });
+      };
+}