Update workflow dependencies

.github/workflows/build-nmage.yml

@@ -0,0 +1,28 @@
+name: build-nmage
+
+on:
+  create:
+  workflow_dispatch:
+
+jobs:
+  build-nmage-macos:
+    runs-on: macos-12
+    steps:
+    
+      - name: Install golang 1.18
+        uses: actions/setup-go@v3
+        with:
+          go-version: '^1.18'
+
+      - name: Install assimp-go dylib
+        run: sudo mkdir -p /usr/local/lib && sudo wget https://github.com/bloeys/assimp-go/releases/download/v0.4.2/libassimp_darwin_amd64.dylib -O /usr/local/lib/libassimp.5.dylib
+
+      - name: Install SDL2
+        run: brew install sdl2{,_image,_mixer,_ttf,_gfx} pkg-config
+
+      - name: Clone nmage
+        run: git clone https://github.com/bloeys/nmage
+
+      - name: build nmage
+        working-directory: nmage
+        run: go build .