Fix gamecube-iso container: install Node.js before checkout

actions/checkout requires Node.js. Install it via apt as a plain shell
step (no Node needed) before the checkout action runs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/build.yml

@@ -137,26 +137,24 @@ jobs:
 
   build-gamecube-iso:
     runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/extremscorner/libogc2:latest
     steps:
+      - name: Install Node.js
+        run: apt-get update && apt-get install -y nodejs
       - name: Checkout repository
         uses: actions/checkout@v4
-      - name: Build GameCube ISO
+      - name: Install additional dependencies
         run: |
-          docker run --rm \
-            -v "${{ github.workspace }}:/workdir" \
-            -w /workdir \
-            ghcr.io/extremscorner/libogc2:latest \
-            /bin/bash -c "
-              apt-get update &&
           apt-get install -y \
-                python3 python3-pip python3-polib python3-pil \
+            python3-pip python3-polib python3-pil \
-                python3-dotenv python3-pyqt5 python3-opengl xorriso &&
+            python3-dotenv python3-pyqt5 python3-opengl xorriso
-              dkp-pacman -Syu --noconfirm &&
+          dkp-pacman -Syu --noconfirm
           dkp-pacman -S --needed --noconfirm \
             gamecube-sdl2 ppc-liblzma ppc-libzip \
-                gamecube-tools ppc-libmad ppc-zlib-ng ppc-bzip2 ppc-zstd &&
+            gamecube-tools ppc-libmad ppc-zlib-ng ppc-bzip2 ppc-zstd
-              ./scripts/build-gamecube-iso.sh
+      - name: Build GameCube ISO
-            "
+        run: ./scripts/build-gamecube-iso.sh
       - name: Copy output files
         run: |
           mkdir -p ./git-artifcats/Dusk